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Ma, Xiaohua, Dehua Deng, Ning Xia, Yuanqiang Hao, and Lin Liu. "Electrochemical Immunosensors with PQQ-Decorated Carbon Nanotubes as Signal Labels for Electrocatalytic Oxidation of Tris(2-carboxyethyl)phosphine." Nanomaterials 11, no. 7 (July 5, 2021): 1757. http://dx.doi.org/10.3390/nano11071757.
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Nanocatalysts are a promising alternative to natural enzymes as the signal labels of electrochemical biosensors. However, the surface modification of nanocatalysts and sensor electrodes with recognition elements and blockers may form a barrier to direct electron transfer, thus limiting the application of nanocatalysts in electrochemical immunoassays. Electron mediators can accelerate the electron transfer between nanocatalysts and electrodes. Nevertheless, it is hard to simultaneously achieve fast electron exchange between nanocatalysts and redox mediators as well as substrates. This work presents a scheme for the design of electrochemical immunosensors with nanocatalysts as signal labels, in which pyrroloquinoline quinone (PQQ) is the redox-active center of the nanocatalyst. PQQ was decorated on the surface of carbon nanotubes to catalyze the electrochemical oxidation of tris(2-carboxyethyl)phosphine (TCEP) with ferrocenylmethanol (FcM) as the electron mediator. With prostate-specific antigen (PSA) as the model analyte, the detection limit of the sandwich-type immunosensor was found to be 5 pg/mL. The keys to success for this scheme are the slow chemical reaction between TCEP and ferricinum ions, and the high turnover frequency between ferricinum ions, PQQ. and TCEP. This work should be valuable for designing of novel nanolabels and nanocatalytic schemes for electrochemical biosensors.
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Roknabadi, Reza, Ali Akbar Mirzaei, and Hossein Atashi. "Assessment of composition and calcination parameters in Fischer-Tropsch synthesis over Fe–Mn–Ce/γ-Al2O3 nanocatalyst." Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 76 (2021): 11. http://dx.doi.org/10.2516/ogst/2020089.
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The effects of nanocatalyst composition and calcination parameters on the performance of the Fe–Mn–Ce ternary nanocatalysts supported on alumina granules in a laboratory fixed bed microreactor have been evaluated. Nanocatalysts were synthesized by incipient wetness impregnation under vacuum method (simultaneous impregnation of metal species). The samples used for hydrogenation of carbon monoxide via Fischer-Tropsch synthesis. The optimum nanocatalyst composition for production of light olefins (C=2 – C=4) from synthesis gas is 75 wt%Fe–20 wt%Mn–5 wt%Ce. The calcination parameters (temperature, time and atmosphere) were investigated and their effects on the structure and performance of the nanocatalysts were determined. The maximum ratio of olefins/(methane + paraffin) and the best activity and selectivity belonged to the nanocatalyst which was calcined in static air at 500 °C for 7 h. The nanocatalyst precursors and calcined samples (fresh and used) were characterized by XRD, N2 physisorption, FE‒SEM, EDAX, MAP, TG, DSC, and H2–TPR. The present study results confirm that the structural, morphological and physic-chemical properties of the nanocatalyst have been impressed with metal species and calcination parameters.
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Pakdehi, Shahram Ghanbari, Maryam Rasoolzadeh, and Reihaneh Zolfaghari. "Synthesize and Investigation of the Catalytic Behavior of Ir/γ-Al2O3 Nanocatalyst." Advanced Materials Research 829 (November 2013): 163–67. http://dx.doi.org/10.4028/www.scientific.net/amr.829.163.
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Hydrazine is an interesting reducing agent which is used in considerable number of different industrial catalytic applications including gas generators, pure hydrogen production for electric fuel cells and monopropellant thrusters. Hydrazine is a highly reactive molecule that decomposes at low temperature on many metal surfaces e. g. iridium, rhodium and tungsten. But the standard commercial catalyst used for decomposition of hydrazine is shell 405 which contents from high metallic content of iridium supported on gamma alumina. In the present study, iridium nanocatalysts based on gamma alumina with metallic content of 20 wt% have been synthesized by the incipient wetness impregnation using H2IrCl6.xH2O as precursor. The pretreatment effects on the metallic accessibility on the Ir/γ-Al2O3 have been evaluated. After ionic exchange, impregnated supports were calcined in air flow and the n followed by reduction in hydrogen flow. The prepared nanocatalyst has been identified using specific surface measurement (BET), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The catalytic mechanism was also briefly discussed. The main goal of this work is prepare, characterize, and determine the nanocatalytic behavior of iridium supported on gamma alumina in decomposition of hydrazine process. The results of this study show that the performance of synthesizes nanocatalyst is suitable for decomposition of hydrazine; however it is need of further investigation. The results indicate that however our synthesized nanocatalyst demonstrates a good job in hydrazine decomposition; some promoters had yet to be tested due to enhancement of economic efficiency.
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Cho, Kie Yong, Yong Sik Yeom, Heun Young Seo, Pradip Kumar, Albert S. Lee, Kyung-Youl Baek, and Ho Gyu Yoon. "Ionic block copolymer doped reduced graphene oxide supports with ultra-fine Pd nanoparticles: strategic realization of ultra-accelerated nanocatalysis." Journal of Materials Chemistry A 3, no. 41 (2015): 20471–76. http://dx.doi.org/10.1039/c5ta06076a.
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Yang, Fan, Dehui Deng, Xiulian Pan, Qiang Fu, and Xinhe Bao. "Understanding nano effects in catalysis." National Science Review 2, no. 2 (May 11, 2015): 183–201. http://dx.doi.org/10.1093/nsr/nwv024.
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Abstract Catalysis, as a key and enabling technology, plays an increasingly important role in fields ranging from energy, environment and agriculture to health care. Rational design and synthesis of highly efficient catalysts has become the ultimate goal of catalysis research. Thanks to the rapid development of nanoscience and nanotechnology, and in particular a theoretical understanding of the tuning of electronic structure in nanoscale systems, this element of design is becoming possible via precise control of nanoparticles’ composition, morphology, structure and electronic states. At the same time, it is important to develop tools for in situ characterization of nanocatalysts under realistic reaction conditions, and for monitoring the dynamics of catalysis with high spatial, temporal and energy resolution. In this review, we discuss confinement effects in nanocatalysis, a concept that our group has put forward and developed over several years. Taking the confined catalytic systems of carbon nanotubes, metal-confined nano-oxides and 2D layered nanocatalysts as examples, we summarize and analyze the fundamental concepts, the research methods and some of the key scientific issues involved in nanocatalysis. Moreover, we present a perspective on the challenges and opportunities in future research on nanocatalysis from the aspects of: (1) controlled synthesis of nanocatalysts and rational design of catalytically active centers; (2) in situ characterization of nanocatalysts and dynamics of catalytic processes; (3) computational chemistry with a complexity approximating that of experiments; and (4) scale-up and commercialization of nanocatalysts.
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Liu, Xiaodong, Tao Chen, and Weilin Xu. "Revealing the thermodynamics of individual catalytic steps based on temperature-dependent single-particle nanocatalysis." Physical Chemistry Chemical Physics 21, no. 39 (2019): 21806–13. http://dx.doi.org/10.1039/c9cp04538d.
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Hamied, Ramzy S., Khalid A. Sukkar, Hasan Shakir Majdi, Zainb Y. Shnain, Mohammed Shorbaz Graish, and Luma H. Mahmood. "Catalytic-Level Identification of Prepared Pt/HY, Pt-Zn/HY, and Pt-Rh/HY Nanocatalysts on the Reforming Reactions of N-Heptane." Processes 11, no. 1 (January 14, 2023): 270. http://dx.doi.org/10.3390/pr11010270.
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The operation of reforming catalysts in a fixed bed reactor undergoes a high level of interaction between the operating parameters and the reaction mechanism. Understanding such an interaction reduces the catalyst deactivation rate. In the present work, three kinds of nanocatalysts (i.e., Pt/HY, Pt-Zn/HY, and Pt-Rh/HY) were synthesized. The catalysts’ performances were evaluated for n-heptane reactions in the fixed bed reactor. The operating conditions applied were the following: 1 bar pressure, WHSV of 4, hydrogen/n-heptane ratio of 4, and the reaction temperatures of 425, 450, 475, 500, and 525 °C. The optimal reaction temperature for all three types of nanocatalysts to produce high-quality isomers and aromatic hydrocarbons was 500 °C. Accordingly, the nanocatalyst Pt-Zn/HY provided the highest catalytic selectivity for the desired hydrocarbons. Moreover, the Pt-Zn/HY-nanocatalyst showed more resistance against catalyst deactivation in comparison with the other two types of nanocatalysts (Pt/HY and Pt-Rh/HY). This work offers more understanding for the application of nanocatalysts in the reforming process in petroleum refineries with high performance and economic feasibility.
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Gao, Yan, Tao Luan, Shitao Zhang, Wenchao Jiang, Wenchen Feng, and Haolin Jiang. "Comprehensive Comparison between Nanocatalysts of Mn−Co/TiO2 and Mn−Fe/TiO2 for NO Catalytic Conversion: An Insight from Nanostructure, Performance, Kinetics, and Thermodynamics." Catalysts 9, no. 2 (February 13, 2019): 175. http://dx.doi.org/10.3390/catal9020175.
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The nanocatalysts of Mn−Co/TiO2 and Mn−Fe/TiO2 were synthesized by hydrothermal method and comprehensively compared from nanostructures, catalytic performance, kinetics, and thermodynamics. The physicochemical properties of the nanocatalysts were analyzed by N2 adsorption, transmission electron microscope (TEM), X-ray diffraction (XRD), H2-temperature-programmed reduction (TPR), NH3-temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). Based on the multiple characterizations performed on Mn−Co/TiO2 and Mn−Fe/TiO2 nanocatalysts, it can be confirmed that the catalytic properties were decidedly dependent on the phase compositions of the nanocatalysts. The Mn−Co/TiO2 sample presented superior structure characteristics than Mn−Fe/TiO2, with the increased surface area, the promoted active components distribution, the diminished crystallinity, and the reduced nanoparticle size. Meanwhile, the Mn4+/Mnn+ ratios in the Mn−Co/TiO2 nanocatalyst were higher than Mn−Fe/TiO2, which further confirmed the better oxidation ability and the larger amount of Lewis acid sites and Bronsted acid sites on the sample surface. Compared to Mn−Fe/TiO2 nanocatalyst, Mn−Co/TiO2 nanocatalyst displayed the preferable catalytic property with higher catalytic activity and stronger selectivity in the temperature range of 75–250 °C. The results of mechanism and kinetic study showed that both Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism reactions contributed to selective catalytic reduction of NO with NH3 (NH3-SCR) over Mn−Fe/TiO2 and Mn−Co/TiO2 nanocatalysts. In this test condition, the NO conversion rate of Mn−Co/TiO2 nanocatalyst was always higher than that of Mn−Fe/TiO2. Furthermore, comparing the reaction between doping transition metal oxides and NH3, the order of temperature−Gibbs free energy under the same reaction temperature is as follows: Co3O4 < CoO < Fe2O3 < Fe3O4, which was exactly consistent with nanostructure characterization and NH3-SCR performance. Meanwhile, the activity difference of MnOx exhibited in reducibility properties and Ellingham Diagrams manifested the promotion effects of cobalt and iron dopings. Generally, it might offer a theoretical method to select superior doping metal oxides for NO conversion by comprehensive comparing the catalytic performance with the insight from nanostructure, catalytic performance, reaction kinetics, and thermodynamics.
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R, Sandhya, Velavan R, and Ravichandran J. "Transesterification of Waste Cooking Oil Catalysed by Crystalline Copper Doped Zinc Oxide Nanocatalyst." JOURNAL OF ADVANCES IN CHEMISTRY 12, no. 12 (December 22, 2016): 5798–808. http://dx.doi.org/10.24297/jac.v12i12.7343.
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Biodiesel has its unique position in the field of renewable energy as alternate fuel to diesel due to fuel price, energy requirement and petroleum crisis. In this study, biodiesel was produced from Waste Cooking Oil (WCO) using Copper doped Zinc Oxide (CZO) nanocatalysts. The synthesized Copper doped Zinc Oxide nanocatalysts were characterized by X-Ray Diffraction (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Design of experiment was framed using Taguchi method to limit the experiments and to find the optimum reaction conditions. The effect of process parameters such as oil-to-methanol ratio (O/M), catalyst type, catalyst concentration, temperature and time on the transesterification reactions using characterized Copper doped Zinc Oxide nanocatalyst were investigated. The 4% (weight /weight) nanocatalyst concentration, 1:5 Oil to methanol molar ratio at 60°C temperature and 40 minutes of reaction time were found to be optimum, in which the maximum biodiesel yield of 98 % (w/w) was obtained. Hence it was determined that nanocatalysts exhibited good catalytic activities on biodiesel production from Waste Cooking Oil (WCO).
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Jang, Sanha, Dicky Annas, Sehwan Song, Jong-Seong Bae, Sungkyun Park, and Kang Hyun Park. "Non-Solvent Synthesis of a Robust Potassium-Doped PdCu-Pd-Cu@C Nanocatalyst for High Selectively Tandem Reactions." Catalysts 11, no. 10 (September 29, 2021): 1191. http://dx.doi.org/10.3390/catal11101191.
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A non-solvent synthesis of alkali metal-doped PdCu-Pd-Cu@C is presented that needs no mechanical grinding and utilizes heat treatment under an N2 gas flow. Pluronic® F127 is used to generate pores and a high surface area, and tannic acid is used as a carbon source for the PdCu-Pd-Cu@C nanocatalysts. Because some C is transferred to organic compounds during the nitrogen heat treatment, this demonstrated the advantage of raising the weight ratio of active metals comparatively. The PdCu-Pd-Cu@C nanocatalyst developed in this study outperformed commercial Pd/C catalysts by bimetallic PdCu-Pd-Cu nanoparticles and Pd nanoparticles in terms of catalytic activity (selectivity of commercial Pd/C: 45%; PdCu-Pd-Cu@C nanocatalyst: 76%). The alkali metal dopants increase the selectivity of the final product on the PdCu-Pd-Cu@C surface because they are electron-rich, which assists in the adsorption of the substrate (selectivity of PdCu-Pd-Cu@C nanocatalyst: 76%; K-doped PdCu-Pd-Cu@C nanocatalysts: 90%). Furthermore, even after being reused 5 times in this research, the final catalytic performance was comparable to that of the initial catalyst.
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Shakil Hussain, S. M., Muhammad Shahzad Kamal, and Mohammad Kamal Hossain. "Recent Developments in Nanostructured Palladium and Other Metal Catalysts for Organic Transformation." Journal of Nanomaterials 2019 (October 20, 2019): 1–17. http://dx.doi.org/10.1155/2019/1562130.
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Nanocatalysis is an emerging field of research and is applicable to nearly all kinds of catalytic organic conversions. Nanotechnology is playing an important role in both industrial applications and academic research. The catalytic activities become pronounced as the size of the catalyst reduces and the surface area-to-volume ratio increases which ultimately enhance the activity and selectivity of nanocatalysts. Similarly, the morphology of the particles also has a great impact on the activity and selectivity of nanocatalysts. Moreover, the electronic properties and geometric structure of nanocatalysts can be affected by polar and nonpolar solvents. Various forms of nanocatalysts have been reported including supported nanocatalysts, Schiff-based nanocatalysts, graphene-based nanocatalysts, thin-film nanocatalysts, mixed metal oxide nanocatalysts, magnetic nanocatalysts, and core-shell nanocatalysts. Among a variety of different rare earth and transition metals, palladium-based nanocatalysts have been extensively studied both in academia and in the industry because of their applications such as in carbon-carbon cross-coupling reactions, carbon-carbon homocoupling reactions, carbon-heteroatom cross-coupling reactions, and C-H activation, hydrogenation, esterification, oxidation, and reduction. The current review highlights the recent developments in the synthesis of palladium and some other metal nanocatalysts and their potential applications in various organic reactions.
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Imtiaz, Ayesha, Muhammad Akhyar Farrukh, Muhammad Khaleeq-ur-rahman, and Rohana Adnan. "Micelle-Assisted Synthesis of Al2O3·CaO Nanocatalyst: Optical Properties and Their Applications in Photodegradation of 2,4,6-Trinitrophenol." Scientific World Journal 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/641420.
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Calcium oxide (CaO) nanoparticles are known to exhibit unique property due to their high adsorption capacity and good catalytic activity. In this work the CaO nanocatalysts were prepared by hydrothermal method using anionic surfactant, sodium dodecyl sulphate (SDS), as a templating agent. The as-synthesized nanocatalysts were further used as substrate for the synthesis of alumina doped calcium oxide (Al2O3·CaO) nanocatalysts via deposition-precipitation method at the isoelectric point of CaO. The Al2O3·CaO nanocatalysts were characterized by FTIR, XRD, TGA, TEM, and FESEM techniques. The catalytic efficiencies of these nanocatalysts were studied for the photodegradation of 2,4,6-trinitrophenol (2,4,6-TNP), which is an industrial pollutant, spectrophotometrically. The effect of surfactant and temperature on size of nanocatalysts was also studied. The smallest particle size and highest percentage of degradation were observed at critical micelle concentration of the surfactant. The direct optical band gap of the Al2O3·CaO nanocatalyst was found as 3.3 eV.
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Olveira, Sandro, Simon P. Forster, and Stefan Seeger. "Nanocatalysis: Academic Discipline and Industrial Realities." Journal of Nanotechnology 2014 (2014): 1–19. http://dx.doi.org/10.1155/2014/324089.
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Nanotechnology plays a central role in both academic research and industrial applications. Nanoenabled products are not only found in consumer markets, but also importantly in business to business markets (B2B). One of the oldest application areas of nanotechnology is nanocatalysis—an excellent example for such a B2B market. Several existing reviews illustrate the scientific developments in the field of nanocatalysis. The goal of the present review is to provide an up-to-date picture of academic research and to extend this picture by an industrial and economic perspective. We therefore conducted an extensive search on several scientific databases and we further analyzed more than 1,500 nanocatalysis-related patents and numerous market studies. We found that scientists today are able to prepare nanocatalysts with superior characteristics regarding activity, selectivity, durability, and recoverability, which will contribute to solve current environmental, social, and industrial problems. In industry, the potential of nanocatalysis is recognized, clearly reflected by the increasing number of nanocatalysis-related patents and products on the market. The current nanocatalysis research in academic and industrial laboratories will therefore enable a wealth of future applications in the industry.
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Masime, Jeremiah Odhek, Erich Okoth Ogur, Betty N. Mbatia, Austin Ochieng' Aluoch, and Geoffrey Otieno. "Characterization of Eggshells Nanocatalyst: Synthesized by Bottom-Up Technology." Walisongo Journal of Chemistry 5, no. 2 (December 25, 2022): 202–11. http://dx.doi.org/10.21580/wjc.v5i2.13434.
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The sol-gel technique was used to prepare the nanocatalyst from waste egg shells for the production of yellow oleander biodiesel. In this study, the physicochemical and catalytic properties of the nanocatalysts were investigated using: X-ray fluorescence spectrometry (XRF), transmission electron microscopy (TEM), the Barrett-Joyner-Halenda (BJH) model to quantify the pore structure of the samples, and Brunauer-Emmett-Teller (BET) to calculate the exact surface area were the techniques used. The results of the EDX, and XRF analysis showed that the synthesized nanocatalyst was majorly CaO. At 90.46 ± 1.73%, this was higher than the control for incinerated eggshells. From TEM images the particles were spherical in shape with particle sizes ranging from ≈ 7 to 41 nm. BET analysis results indicated that the nanocatalyst was mesoporous with surface area, average pore diameter, and pore volume was; 5.54 ± 0.48 m2/g, 18.57 ± 2.16 nm, and ≈ 0.016 ± 0.0 – 0.017 ± 0.0 cm³/g, respectively. The surface area to volume ratios were 3.27 ± 108 m-1, 2.52 ± 108, and 1.95 ± 108 m-1, respectively. Incinerated eggshells highest followed the synthesized nanocatalyst and CaO, respectively. The synthesized eggshell nanocatalyst was found to be a potential nanocatalyst.
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Poonsawat, Thinnaphat, Thanyaphat Techalertmanee, Peerapong Chumkaeo, Isti Yunita, Titiya Meechai, Montree Namkajorn, Soraya Pornsuwan, and Ekasith Somsook. "Facile Synthesis of High Performance Iron Oxide/Carbon Nanocatalysts Derived from the Calcination of Ferrocenium for the Decomposition of Methylene Blue." Catalysts 9, no. 11 (November 12, 2019): 948. http://dx.doi.org/10.3390/catal9110948.
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Iron oxide/carbon nanocatalysts were successfully synthesized by the calcination of ferrocenium at high temperatures ranging from 500 to 900 °C. Then the synthesized nanocomposites were characterized by XRD (X-Ray Diffraction), TEM (Transmission Electron Microscopy), VSM (Vibrating-Sample Magnetometry), BET (Brunauer-Emmett-Teller surface area measurements), TGA (Thermogravimetric Analysis), XPS (X-Ray Photoelectron Spectroscopy), EPR (Electron Paramagnetic Resonance), and CHN elemental analysis. The prepared nanocatalysts were applied for the decomposition of methylene blue as a model in wastewater treatment. It was unexpected to discover that the prepared nanocatalysts were highly active for the reaction with methylene blue in the dark even though no excess of hydrogen peroxide was added. The nanocatalyst calcined at 800 °C exhibited the rod shape with the best catalytic activity. The nanocatalysts could be reused for 12 times without the significant loss of the catalytic activity.
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Chowdhury, Keya, Akter Hossain Reaz, Chanchal Kumar Roy, and Al-Nakib Chowdury. "Fabrication of a Highly Active Ni-SiO2 Nanocatalyst and Study of Its Catalytic Efficacy Toward the Reduction of Nitroaromatics." ECS Transactions 107, no. 1 (April 24, 2022): 16035–40. http://dx.doi.org/10.1149/10701.16035ecst.
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Transition metal-based nanocatalysts have gained desirable interest in catalysis because of their high activity, low cost, and ease of recycling in chemical reactions. In this work, nanoporous SiO2 nanoparticles (NPs) were employed as the support to immobilize Ni NPs based nanocatalyst (with a mass ratio of 2:2 of SiO2 and Ni) by a facile in-situ reduction in a controlled medium. FTIR analysis was employed to investigate the chemical nature of the prepared Ni-SiO2 nanocatalyst, which revealed the formation of Ni NPs onto the surface of nanoporous SiO2 NPs. The catalytic efficacy of the prepared nanocatalyst was inspected through the probe reduction process of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) via UV‒vis absorption spectroscopy. Ni-SiO2 nanocatalyst showed good catalytic activity and successfully converted 4-NP to 4-AP sufficiently within 10 min. The computed rate constant, k, and activity parameter, K, was 0.069 min-1 and 34.5 g-1 min-1.
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Ghamari kargar, Pouya, and Ghodsieh Bagherzade. "The anchoring of a Cu(ii)–salophen complex on magnetic mesoporous cellulose nanofibers: green synthesis and an investigation of its catalytic role in tetrazole reactions through a facile one-pot route." RSC Advances 11, no. 31 (2021): 19203–20. http://dx.doi.org/10.1039/d1ra01913a.
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Due to the importance and widespread applications of tetrazoles, especially in pharmaceutical chemistry, and the expansion of the use of nanocatalysts in the preparation of valuable chemical reaction products, we decided to use a (Fe3O4@NFC@NSalophCu)CO2H nanocatalyst.
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Gao, Yan, Wenchao Jiang, Tao Luan, Hui Li, Wenke Zhang, Wenchen Feng, and Haolin Jiang. "High-Efficiency Catalytic Conversion of NOx by the Synergy of Nanocatalyst and Plasma: Effect of Mn-Based Bimetallic Active Species." Catalysts 9, no. 1 (January 18, 2019): 103. http://dx.doi.org/10.3390/catal9010103.
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Three typical Mn-based bimetallic nanocatalysts of Mn−Fe/TiO2, Mn−Co/TiO2, Mn−Ce/TiO2 were synthesized via the hydrothermal method to reveal the synergistic effects of dielectric barrier discharge (DBD) plasma and bimetallic nanocatalysts on NOx catalytic conversion. The plasma-catalyst hybrid catalysis was investigated compared with the catalytic effects of plasma alone and nanocatalyst alone. During the catalytic process of catalyst alone, the catalytic activities of all tested catalysts were lower than 20% at ambient temperature. While in the plasma-catalyst hybrid catalytic process, NOx conversion significantly improved with discharge energy enlarging. The maximum NOx conversion of about 99.5% achieved over Mn−Ce/TiO2 under discharge energy of 15 W·h/m3 at ambient temperature. The reaction temperature had an inhibiting effect on plasma-catalyst hybrid catalysis. Among these three Mn-based bimetallic nanocatalysts, Mn−Ce/TiO2 displayed the optimal catalytic property with higher catalytic activity and superior selectivity in the plasma-catalyst hybrid catalytic process. Furthermore, the physicochemical properties of these three typical Mn-based bimetallic nanocatalysts were analyzed by N2 adsorption, Transmission Electron Microscope (TEM), X-ray diffraction (XRD), H2-temperature-programmed reduction (TPR), NH3-temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). The multiple characterizations demonstrated that the plasma-catalyst hybrid catalytic performance was highly dependent on the phase compositions. Mn−Ce/TiO2 nanocatalyst presented the optimal structure characteristic among all tested samples, with the largest surface area, the minished particle sizes, the reduced crystallinity, and the increased active components distributions. In the meantime, the ratios of Mn4+/(Mn2+ + Mn3+ + Mn4+) in the Mn−Ce/TiO2 sample was the highest, which was beneficial to plasma-catalyst hybrid catalysis. Generally, it was verified that the plasma-catalyst hybrid catalytic process with the Mn-based bimetallic nanocatalysts was an effective approach for high-efficiency catalytic conversion of NOx, especially at ambient temperature.
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Li, Yiyang, Guanyan Li, Yafeng Yang, Xiangmeng Chen, Wanxi Peng, and Hanyin Li. "Incorporation of Nanocatalysts for the Production of Bio-Oil from Staphylea holocarpa Wood." Polymers 14, no. 20 (October 17, 2022): 4385. http://dx.doi.org/10.3390/polym14204385.
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Biomass has been recognized as the most common source of renewable energy. In recent years, researchers have paved the way for a search for suitable biomass resources to replace traditional fossil fuel energy and provide high energy output. Although there are plenty of studies of biomass as good biomaterials, there is little detailed information about Staphylea holocarpa wood (S. holocarpa) as a potential bio-oil material. The purpose of this study is to explore the potential of S. holocarpa wood as a bio-oil. Nanocatalyst cobalt (II) oxide (Co3O4) and Nickel (II) oxide (NiO) were used to improve the production of bio-oil from S. holocarpa wood. The preparation of biofuels and the extraction of bioactive drugs were performed by the rapid gasification of nanocatalysts. The result indicated that the abundant chemical components detected in the S. holocarpa wood extract could be used in biomedicine, cosmetics, and biofuels, and have a broad industrial application prospect. In addition, nanocatalyst cobalt tetraoxide (Co3O4) could improve the catalytic cracking of S. holocarpa wood and generate more bioactive molecules at high temperature, which is conducive to the utilization and development of S. holocarpa wood as biomass. This is the first time that S. holocarpa wood was used in combination with nanocatalysts. In the future, nanocatalysts can be used to solve the problem of sustainable development of biological resources.
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Ji, Fengtong, Ben Wang, and Li Zhang. "Light-Triggered Catalytic Performance Enhancement Using Magnetic Nanomotor Ensembles." Research 2020 (July 8, 2020): 1–11. http://dx.doi.org/10.34133/2020/6380794.
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Micro/nanomachines have attracted extensive attention in the biomedical and environmental fields for realizing functionalities at small scales. However, they have been rarely investigated as active nanocatalysts. Heterogeneous nanocatalysts have exceptional reusability and recyclability, and integration with magnetic materials enables their recovery with minimum loss. Herein, we propose a model active nanocatalyst using magnetic nanomotor ensembles (MNEs) that can degrade contaminants in an aqueous solution with high catalytic performance. MNEs composed of a magnetite core coated with gold nanoparticles as the nanocatalyst can rotate under the action of a programmable external field and carry out rapid reduction of 4-nitrophenol (4-NP). The hydrogen bubbles generated in the catalytic reaction provide random perturbations for the MNEs to travel in the reaction solution, resulting in uniform processing. The reduction can be further boosted by irradiation with near-infrared (NIR) light. Magnetic field induces the rotation of the MNEs and provides microstirring in the catalysis. Light enhances the catalytic activity via the photothermal effect. These MNEs are also capable of moving to the targeted region through the application of a programmable magnetic field and then process the contaminant in the targeted region. We expect that such magnetic MNEs may help better in applying active heterogeneous nanocatalysts with magnetic field and light-enhanced performance in industrial applications due to their advantages of low material cost and short reaction time.
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Alfaro-López, Hilda M., Manuel A. Valdés-Madrigal, Hugo Rojas-Chávez, Heriberto Cruz-Martínez, Miguel A. Padilla-Islas, Miriam M. Tellez-Cruz, and Omar Solorza-Feria. "A Trimetallic Pt2NiCo/C Electrocatalyst with Enhanced Activity and Durability for Oxygen Reduction Reaction." Catalysts 10, no. 2 (February 2, 2020): 170. http://dx.doi.org/10.3390/catal10020170.
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Commercialization of the polymer electrolyte membrane fuel cell (PEMFC) requires that electrocatalysts for oxygen reduction reaction (ORR) satisfy two main considerations: materials must be highly active and show long-term stability in acid medium. Here, we describe the synthesis, physical characterization, and electrochemical evaluation of carbon-dispersed Pt2NiCo nanocatalysts for ORR in acid medium. We synthesized a trimetallic electrocatalyst via chemical route in organic medium and investigated the physical properties of the Pt2NiCo/C nanocatalyst by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy-scanning electron microscope (EDXS-SEM), and scanning transmission electron microscopy (STEM), whereas the catalytic activities of the Pt2NiCo/C and Pt/C nanocatalysts were determined through cyclic voltammetry (CV), CO-stripping, and rotating disk electrode (RDE) electrochemical techniques. XRD and EDXS-SEM results confirmed the presence of the three metals in the nanoparticles, and scanning transmission electron microscopy (STEM) allowed observation of the Pt2NiCo nanoparticles at ~10 nm. The measured specific activity for the synthesized nanocatalyst is ~6.4-fold higher than that of Pt/C alone, and its mass activity is ~2.2-fold higher than that of Pt/C, which is attributed to the synergistic interaction of the trimetallic electrocatalyst. Furthermore, the specific and mass activities of the synthesized material are maintained after the accelerated stability test, whereas the catalytic properties of Pt/C decreased. These results suggest that the Pt2NiCo/C trimetallic nanocatalyst is a promising candidate cathode electrode for use in PEMFCs.
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Tasfy, Sara Faiz Hanna, Noor Asmawati Mohd Zabidi, and Duvvuri Subbarao. "Effects of Cu and K Promoters on the Catalytic Performance of Iron-Based Nanocatalyst for Fischer-Tropsch Synthesis." Advanced Materials Research 832 (November 2013): 15–20. http://dx.doi.org/10.4028/www.scientific.net/amr.832.15.
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Iron-based nanocatalyst was prepared via impregnation method on SiO2 support. The effects of promoters, namely, K and Cu, on the physical properties and catalytic performance in FTS have been investigated. The FTS performance of the synthesized nanocatalysts was examined in a fixed-bed microreactor at temperature of 523K, atmospheric pressure, 1.5 reactant ratio (H2/CO) and space velocity of 3L/g-cat.h. In FTS reaction, Cu promoter resulted in a lower CO conversion and C5+ hydrocarbons selectivity but higher selectivity to the lighter hydrocarbons (C1-C4) comparedto those obtained using the K promoter. Higher CO conversion (28.9%) and C5+ hydrocarbons selectivity (54.4%) were obtained using K as a promoter compared to that of Cu promoter. However, the K-promoted nanocatalyst resulted in a lower CO conversion but higher selectivity of the heavy hydrocarbons (C5+) compared to those obtained using the un-promoted nanocatalyst.
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Cintron-Nuñez, P. C., B. Escobar-Morales, J. Escorcia-Garcia, F. J. Rodríguez-Varela, and I. L. Alonso-Lemus. "Electrospun CoFe2O4 nanofibers as bifunctional nanocatalysts for the oxygen evolution and oxygen reduction reactions in alkaline media." MRS Advances 5, no. 57-58 (2020): 2929–37. http://dx.doi.org/10.1557/adv.2020.380.
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AbstractNon-noble metal bifunctional nanocatalysts based on CoFe2O4/C were synthetized by the electrospinning method and evaluated for the Oxygen Evolution Reaction (OER) and the Oxygen Reduction Reaction (ORR). The effect of annealing at different temperatures (T=300, 600 and 900°C) on their morphological and structural features was characterized by XRD, EDS, Raman, FESEM, HRTEM and XPS. The nanofibers annealed at 300 °C (CoFe2O4-300) showed a cubic spinel structure and an average diameter of 42 nm. The CoFe2O4-300/C nanocatalyst demonstrated the highest catalytic activity towards the OER, outperforming the benchmark commercial 20 wt. % Pt/C. Meanwhile all CoFe2O4-based nanocatalysts showed fair catalytic activity for the ORR (Eonset ≈ 0.801 V/RHE, n≈ 3.56, %HO2- ≈ 21-39). In addition, the CoFe2O4/C nanocatalysts demonstrated a higher electrochemical stability than Pt/C for both the ORR and the OER.
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Rana, Shikha, and Mahavir Singh. "A Brief Review on the Use of Ferrite in Catalysis." ECS Transactions 107, no. 1 (April 24, 2022): 9591–99. http://dx.doi.org/10.1149/10701.9591ecst.
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The developing eminently capable nanocatalyst is a befitting need of catalytic industries. This brief review provides knowledge about the recent advances in use of nanoferrite composites in various catalytic processes like immobilization of enzymes, degradation of harmful contaminants in waste water, synthesis of biofuel. Easy deactivation, less recovery, and low stability like limitations of traditional catalysts are transcended by peculiar nanocatalysts. With latest advancement in synthesis, functionalization and designing techniques the preparation process of efficient ferrite nanocatalyst hybrids is optimized. The various catalytic applications of spinel ferrites are due to facile recovery, stability, and activity provided by ferrites in catalytic processes. In the present article, the behavior of ferrite as biocatalyst, Fenton catalyst and photocatalyst have been briefly reviewed and summarized.
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Kuniyil, Mufsir, J. V. Shanmukha Kumar, Syed Farooq Adil, Mohammed Rafi Shaik, Mujeeb Khan, Mohamed E. Assal, Mohammed Rafiq H. Siddiqui, and Abdulrahman Al-Warthan. "One-Pot Synthesized Pd@N-Doped Graphene: An Efficient Catalyst for Suzuki–Miyaura Couplings." Catalysts 9, no. 5 (May 21, 2019): 469. http://dx.doi.org/10.3390/catal9050469.
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Nitrogen-doped graphene (NDG)-palladium (Pd)-based nanocatalysts (NDG@Pd) can be potentially applied as an efficient catalyst for the preparation of biaryls in a Suzuki–Miyaura coupling reaction. Herein, we report the one-pot facile synthesis of an NDG@Pd nanocatalyst, wherein the nanocatalyst was prepared by the simultaneous reduction of graphene oxide (GRO) and PdCl2 in the presence of hydrazine hydrate as a reducing agent, while ammonium hydroxide was used as a source of “N’’ on the surface of graphene. The as-synthesized NDG@Pd nanocatalyst, consisting of smaller-sized, spherical-shaped palladium nanoparticles (Pd-NPs) on the surface of NDG, was characterized by several spectroscopic and microscopic techniques, including high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), ultraviolet–visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET). The nanocatalyst displayed outstanding catalytic activity in the Suzuki–Miyaura cross-coupling reactions of phenyl halides with phenyl boronic acids under facile conditions in water. The catalytic activity of NDG@Pd was found to be a more efficient catalyst when compared to pristine highly reduced graphene oxide (HRG) based Pd nanocatalyst (HRG@Pd). Furthermore, the reusability of the catalyst was also tested by repeatedly performing the same reaction using the recovered catalyst. The N-doped catalyst displayed excellent reusability even after several reactions.
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Bharti, Priyanka, Bhaskar Singh, and R. K. Dey. "Process optimization of biodiesel production catalyzed by CaO nanocatalyst using response surface methodology." Journal of Nanostructure in Chemistry 9, no. 4 (September 24, 2019): 269–80. http://dx.doi.org/10.1007/s40097-019-00317-w.
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Abstract Uses of nanocatalysts have become more useful in optimizing catalytic reactions. They are known to enhance the rate of reaction by offering a greater number of active sites by possessing a high surface-to-volume ratio. In the present work, calcium oxide nanocatalysts were synthesized through the sol–gel method. The particle size of the nanocatalyst prepared ranged up to 8 nm. Soybean oil was used as the raw material for the synthesis of biodiesel. The synthesized nano-CaO was characterized through scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and BET (Brunauer–Emmett–Teller). Average BET surface area analysis of the nanocatalyst was calculated to be 67.781 m2/g and pore diameter was 3.302 nm. Nano-CaO catalyst was used to synthesize biodiesel and optimize the reaction variables through optimization processes to achieve a high yield of biodiesel. The reaction variables that were optimized were catalyst amount, oil to methanol molar ratio and reaction temperature. Upon optimization, the conversion of biodiesel was found to be 97.61%. The optimized value of the reaction variables was: catalyst amount of 3.675 wt% with respect to oil, molar ratio (alcohol to oil) of 11:1, and reaction temperature of 60 °C for 2 h. Graphic abstract
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Zahid, Afifa, Zahid Mukhtar, Muhammad Azam Qamar, Sammia Shahid, Syed Kashif Ali, Mohammad Shariq, Hussain J. Alathlawi, et al. "Synthesis of Mn-Doped ZnO Nanoparticles and Their Application in the Transesterification of Castor Oil." Catalysts 13, no. 1 (January 3, 2023): 105. http://dx.doi.org/10.3390/catal13010105.
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Alarming environmental changes and the threat of natural fuel resource extinction are concerning issues in human development. This has increased scientists’ efforts to phase out traditional energy resources and move on to environmentally friendly biofuels. In this study, non-edible castor oil was transesterified with methanol using a manganese-doped zinc oxide (Mn-doped ZnO) nanocatalyst. A heterogeneous nanocatalyst was prepared by means of the the sonochemical method. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) were used to characterize these nanocatalysts. The transesterification reaction was studied under different temperature conditions, different ratios of methyl alcohol to castor oil, and different amounts of the catalyst to identify optimum conditions in which the maximum yield of biodiesel was produced. The maximum biodiesel yield (90.3%) was observed at 55 °C with an oil-to-methanol ratio of 1:12, and with 1.2 g of nanocatalyst. The first-order kinetic model was found to be the most suitable. Several thermodynamic parameters were also determined, such as activation energy, enthalpy, and entropy. We found that this transesterification was an endergonic and entropy-driven reaction. The results showed that the Mn-doped ZnO nanocatalyst could be a suitable catalyst for the heterogeneous catalytic transesterification process, which is essential for biodiesel production.
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Ma, Ju Gang, Jun Mei Wang, Shuai Li, and Yu Jun Song. "Microfluidic Synthesis and Electrochemical Performance of Ternary Metals Nanoalloy: FePtSn." Materials Science Forum 913 (February 2018): 831–37. http://dx.doi.org/10.4028/www.scientific.net/msf.913.831.
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The ternary FePtSn alloy nanoparticles (NPs) were synthesized via a simple programmed microfluidic process, showing a great electrochemical performance in methanol oxidation reaction (MOR). The synthesis process exhibited convenient and spatial-temporal kinetics control of the NPs formation for a narrow size distribution, ultra-small (~2nm) and good dispersion features. The morphology, crystal structure and composition of FePtSn NPs were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD). FePtSn/C nanocatalyst ink could be further prepared by mixing the as-synthesized or annealed FePtSn NPs with carbon black powder and nafion. Their electrocatalytic performances were tested by the electrochemical work station. By contrast, the annealing treatment made more active sites exposed and facilitated the catalytic performance of FePtSn/C NPs. The electrochemical active surface areas (ECSAs, 42.8m2/g), catalytic activity (If: 588.1 mA/mg-Pt) and electrochemical durability of FePtSn/C nanocatalysts after annealing were greatly improved, comparing with as-synthesized samples and commercial Pt/C nanocatalysts for MOR. In addition, the onset potential of annealed FePtSn/C nanocatalysts was improved, much better than the commercial Pt/C nanocatalysts.
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Corchero, Raquel, Rosario Rodil, Ana Soto, and Eva Rodil. "Nanomaterial Synthesis in Ionic Liquids and Their Use on the Photocatalytic Degradation of Emerging Pollutants." Nanomaterials 11, no. 2 (February 5, 2021): 411. http://dx.doi.org/10.3390/nano11020411.
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The unique properties of ionic liquids make them suitable candidates to prepare nanoscale materials. A simple method that uses exclusively a corresponding bulk material and an ionic liquid—in this case, [P6,6,6,14]Cl—was used to prepare AgCl nanoparticles and AgCl@Fe3O4 or TiO2@Fe3O4 magnetic nanocomposites. The prepared nanomaterials were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet–visible spectroscopy, and X-ray photoelectron spectroscopy. The photodegradation of atenolol as a model pharmaceutical pollutant in wastewater was investigated under ultraviolet–visible light irradiation using the different synthesized nanocatalysts. In the presence of 0.75 g·L−1 AgCl nanoparticles, a practically complete degradation of 10 ppm of atenolol was obtained after 30 min, following pseudo-first-order reaction kinetics. The effect of different variables (concentrations, pH, oxidant agents, etc.) was analyzed. The recyclability of the nanocatalyst was tested and found to be successful. A degradation mechanism was also proposed. In order to improve the recovery stage of the nanocatalyst, the use of magnetic nanocomposites is proposed. Under the same experimental conditions, a slightly lower and slower degradation was achieved with an easier separation. The main conclusions of the paper are the suitability of the use of ionic liquids to prepare different nanocatalysts and the effectiveness of these at degrading an emerging pollutant in wastewater treatment.
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Yavari, Khadijeh, Bagher Eftekhari-Sis, and Ali Akbari. "Synthesis and Application of Silver and Cobalt Nanoparticles Immobilized on Ionic Liquid-Functionalized Halloysite Nanotubes in the Reduction of 4-Nitrophenol in Aqueous Solution." Nano 16, no. 08 (July 2021): 2150089. http://dx.doi.org/10.1142/s1793292021500892.
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4-nitrophenol (4-NP) is a highly toxic pollutant for aquatic ecosystem and human life. Therefore, the catalytic reduction of 4-NP into useful 4-aminophenol (4-AP) is of interest. In this regard, two heterogeneous nanocatalysts, including Ag@HNTs-ILs and Co@HNTs-ILs were prepared by grafting imidazolium-based ionic liquids (ILs) onto the halloysite nanotubes (HNTs), followed by immobilization of Ag and Co nanoparticles (NPs), and characterized by means of FT-IR, SEM, EDX, TEM and XRD. The catalytic activity of the prepared nanocatalysts was evaluated for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) under environmentally friendly condition. A set of time, temperature, nanocatalyst amount and NaBH4/4-NP molar ratios was screened. The reusability experiments demonstrated that Ag@HNTs-ILs and Co@HNTs-ILs were highly reusable, up to five reduction cycles without considerable changes in the reaction time. As the synthesized hybrid nanocatalysts could be re-collected and reused for various catalytic runs without any significant loss in their catalytic activity, they could be considered very promising nanomaterials from sustainability point of view.
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Bai, Xiaoyan, Tianqi Cao, Tianyu Xia, Chenxiao Wu, Menglin Feng, Xinru Li, Ziqing Mei, et al. "MoS2/NiSe2/rGO Multiple-Interfaced Sandwich-like Nanostructures as Efficient Electrocatalysts for Overall Water Splitting." Nanomaterials 13, no. 4 (February 16, 2023): 752. http://dx.doi.org/10.3390/nano13040752.
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Constructing a heterogeneous interface using different components is one of the effective measures to achieve the bifunctionality of nanocatalysts, while synergistic interactions between multiple interfaces can further optimize the performance of single-interface nanocatalysts. The non-precious metal nanocatalysts MoS2/NiSe2/reduced graphene oxide (rGO) bilayer sandwich-like nanostructure with multiple well-defined interfaces is prepared by a simple hydrothermal method. MoS2 and rGO are layered nanostructures with clear boundaries, and the NiSe2 nanoparticles with uniform size are sandwiched between both layered nanostructures. This multiple-interfaced sandwich-like nanostructure is prominent in catalytic water splitting with low overpotential for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) and almost no degradation in performance after a 20 h long-term reaction. In order to simulate the actual overall water splitting process, the prepared nanostructures are assembled into MoS2/NiSe2/rGO||MoS2/NiSe2/rGO modified two-electrode system, whose overpotential is only 1.52 mV, even exceeded that of noble metal nanocatalyst (Pt/C||RuO2~1.63 mV). This work provides a feasible idea for constructing multi-interface bifunctional electrocatalysts using nanoparticle-doped bilayer-like nanostructures.
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Guerrero, Miguel, Nguyet Trang Thanh Chau, Alain Roucoux, Audrey Nowicki-Denicourt, Eric Monflier, Hervé Bricout, and Karine Philippot. "Organometallic synthesis of water-soluble ruthenium nanoparticles in the presence of sulfonated diphosphines and cyclodextrins." MRS Proceedings 1675 (2014): 219–25. http://dx.doi.org/10.1557/opl.2014.888.
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ABSTRACTThe organometallic approach was successfully applied to synthesize water-soluble ruthenium nanoparticles displaying interesting catalytic properties in hydrogenation of unsaturated model-substrates. Nanocatalyst synthesis was performed by hydrogenation of the complex [Ru(COD)(COT)] in the presence of sulfonated diphosphines and cyclodextrins as protective agents providing very small ruthenium nanoparticles (ca. 1.2-1.5 nm) with narrow size distribution and high stability. Catalysis results in water evidenced a control of the surface properties of these novel ruthenium nanocatalysts at a supramolecular level.
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Pratiwi, Dian. "Synthesis of Fe3O4 Nanocatalyst Capped Citric Acid (Fe3O4-CA) from Sargassum filipendula." ALKIMIA : Jurnal Ilmu Kimia dan Terapan 5, no. 2 (February 28, 2022): 173–80. http://dx.doi.org/10.19109/alkimia.v5i2.11307.
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The nanocatalyst Fe3O4 capped citric acid (Fe3O4-CA) was successfully synthesized using brown seaweed Sargassum filipendula. Sulfated polysaccharides contained in Sargassum filipendula extract contain sulfate, hydroxy, and aldehyde groups which cause Fe3+ reduction and nanoparticle stabilization. The FT-IR results of Sargassum filipendula extract showed the presence of CO-SO3 stretching vibrations at 1040 cm-1, sulfate groups at 1241 cm-1, aromatic CC at 1413 cm-1, carbonyl at 1604 cm-1, CH stretching vibrations at 2932 cm-1. 1, and the hydroxy group at 3316 cm-1\. Meanwhile, citric acid was used as capping to prevent agglomeration of the synthesized nanocatalyst. Fe3O4-CA nanocatalysts were characterized using XRD, PSA, and SEM-EDX. The XRD results were processed using the Debye-Scherrer equation and the crystal size of Fe3O4-CA was 8.5 nm. PSA results show that Fe3O4-CA particles have a radius of 45.09 nm or diameter of 90.18 nm. This nanocatalyst was also tested for the synthesis of pyrimidine-derived compounds at optimum conditions using 7.5% mol of catalyst, 50 °C for 6 hours, in order to obtain a yield of 83.2%.
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Hansen, Henrik E., Daniel Ø. Fakhri, Frode Seland, Svein Sunde, Odne S. Burheim, and Bruno G. Pollet. "Sonochemical Synthesis of Cu@Pt Bimetallic Nanoparticles." Molecules 27, no. 16 (August 18, 2022): 5281. http://dx.doi.org/10.3390/molecules27165281.
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Reducing the amount of noble metals in catalysts for electrochemical conversion devices is paramount if these devices are to be commercialized. Taking advantage of the high degree of particle property control displayed by the sonochemical method, we set out to synthesize Cu@Pt bimetallic nanocatalysts in an effort to improve the mass activity towards the hydrogen evolution reaction. At least 17 times higher mass activity was found for the carbon supported Cu@Pt bimetallic nanocatalyst (737 mA mg−1, E = −20 mV) compared to carbon supported Pt nanocatalysts prepared with the same ultrasound conditions (44 mA mg−1, E = −20 mV). The synthesis was found to proceed with the sonochemical formation of Cu and Cu2O nanoparticles with the addition of PtCl4 leading to galvanic displacement of the Cu-nanoparticles and the formation of a Pt-shell around the Cu-core.
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Lari, Tahereh Taherzadeh, Ali Akbar Mirzaei, Hossein Atashi, and Hamid Reza Bozorgzadeh. "A Modeling Study of Operating Conditions and Different Supports on Fe-Co-Ce Nanocatalyst and Optimizing of Light Olefins Selectivity in the Fischer-Tropsch Synthesis." Chemistry & Chemical Technology 15, no. 2 (May 15, 2021): 170–82. http://dx.doi.org/10.23939/chcht15.02.170.
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This study demonstrates the effect of operating conditions (Red-GHSV, inlet H2/CO, Oprat-GHSV) and the effect of Fe-Co-Ce nanocatalyst support. A statistical model using the response surface methodology (RSM) was applied with the target of achieving higher olefins selectivity in Fischer-Tropsch synthesis, which indicates the interaction effects of factors. The conditions under which three objectives optimization for maximizing olefins and minimizing paraffins and methane were determined. Synthesized nanocatalysts with various supports were characterized by XRD, SEM and TPR techniques
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Wang, Wenhu, Mallikarjuna N. Nadagouda, and Sharmila M. Mukhopadhyay. "Advances in Matrix-Supported Palladium Nanocatalysts for Water Treatment." Nanomaterials 12, no. 20 (October 13, 2022): 3593. http://dx.doi.org/10.3390/nano12203593.
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Advanced catalysts are crucial for a wide range of chemical, pharmaceutical, energy, and environmental applications. They can reduce energy barriers and increase reaction rates for desirable transformations, making many critical large-scale processes feasible, eco-friendly, energy-efficient, and affordable. Advances in nanotechnology have ushered in a new era for heterogeneous catalysis. Nanoscale catalytic materials are known to surpass their conventional macro-sized counterparts in performance and precision, owing it to their ultra-high surface activities and unique size-dependent quantum properties. In water treatment, nanocatalysts can offer significant promise for novel and ecofriendly pollutant degradation technologies that can be tailored for customer-specific needs. In particular, nano-palladium catalysts have shown promise in degrading larger molecules, making them attractive for mitigating emerging contaminants. However, the applicability of nanomaterials, including nanocatalysts, in practical deployable and ecofriendly devices, is severely limited due to their easy proliferation into the service environment, which raises concerns of toxicity, material retrieval, reusability, and related cost and safety issues. To overcome this limitation, matrix-supported hybrid nanostructures, where nanocatalysts are integrated with other solids for stability and durability, can be employed. The interaction between the support and nanocatalysts becomes important in these materials and needs to be well investigated to better understand their physical, chemical, and catalytic behavior. This review paper presents an overview of recent studies on matrix-supported Pd-nanocatalysts and highlights some of the novel emerging concepts. The focus is on suitable approaches to integrate nanocatalysts in water treatment applications to mitigate emerging contaminants including halogenated molecules. The state-of-the-art supports for palladium nanocatalysts that can be deployed in water treatment systems are reviewed. In addition, research opportunities are emphasized to design robust, reusable, and ecofriendly nanocatalyst architecture.
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Muneer, Iqra, Muhammad Akhyar Farrukh, Shaghraf Shaghraf, Muhammad Khaleeq-Ur-Rahman, Akrajas Ali Umar, and Rohana Adnan. "Solvent Controlled Synthesis of Tin Oxide Nanocatalysts and their Applications in Photodegradation of Environmental Hazardous Materials." Materials Science Forum 756 (May 2013): 197–204. http://dx.doi.org/10.4028/www.scientific.net/msf.756.197.
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Solvent controlled synthesis of tin oxide nanocatalysts were prepared via the hydrothermal method. To study the effect of solvent on the particle size of tin oxide and their catalytic efficiency on photodegradation of environmental hazardous materials, the synthesis was carried out at different concentrations of solvent (isoamyl alcohol) keeping all other reaction conditions constant. The nanoparticles were characterized by FourierTransmission Infrared Spectroscopy, Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray Diffraction and Thermogravimetric analysis. Prepared nanoparticles were applied as nanocatalyst under UV-visible light for the photodegradation of methyl green,which is an abundant organic pollutant of industrial waste water. Photodegradation activities of the nanocatalysts were measured in three different ways, i. pseudo first order rate constant, “k”. ii. percentage degradationand iii. degradation rate. Effect of solvent was quantitatively explained in term of double sphere model of ion-ion interaction. Degradation of pollutants was also monitored by High Performance Liquid Chromatography.
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Khairy, Mohamed, and Sherif A. El Safty. "Water Treatment through Chemical Transformation and Elimination of Organic Toxin Based on Mesoporous Nickel Oxide Nanocrystals." Advanced Materials Research 685 (April 2013): 139–44. http://dx.doi.org/10.4028/www.scientific.net/amr.685.139.
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The development of sustainable catalyst could potentially provide a long-term solution for the industrial process that required production of a large quantity of raw materials for the chemical industry from renewable resources. Hence, achieving proper designs of highly efficient, sustainable and long-term reusable catalyst is one of the environmentally crucial issues facing humanity. Here, we report the fabrication of mesoporous NiO nanocatalyst in different morphology via a simple hydrothermal method. The mesoporous NiO nanocatalysts exhibit high catalytic activity and fast removal of toxic chemical agents from aquatic life.
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Shiri, Lotfi, Arash Ghorbani-Choghamarani, and Mosstafa Kazemi. "Sulfides Synthesis: Nanocatalysts in C–S Cross-Coupling Reactions." Australian Journal of Chemistry 69, no. 6 (2016): 585. http://dx.doi.org/10.1071/ch15528.
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The C–S cross-coupling reaction of aryl halides with thiols or sulfur sources is a key and valuable synthetic transformation in chemistry and medicine as well as in biology, and the development of novel efficient synthetic protocols for the synthesis of the corresponding products (sulfides) is highly desired. Among a wide range of catalysts used in C–S coupling reactions, metallic nanocatalysts have attracted notable interest. Herein, we summarize recent breakthroughs in the arena of metal nanocatalysts employed in C–S cross-coupling reactions with the goal of stimulating further progress in this field. This review is divided into three main sections according to the nature of the metal nanocatalysts discussed. The first section focuses on naked or purely metallic catalysts in nano-size, such as Cu, Pd, Ni, and In. The second section focuses on the role of Fe3O4 magnetic nanoparticles and mesoporous silica nanomaterials, such as MCM-41 and SBA-15, as catalyst supports. Finally, the third section focuses on the catalytic activities of copper ferrite nanoparticles in C–S cross-coupling reactions. Additionally, the recovery and reusability of the nanocatalyst, which are very important from commercial and economical points of view, are comprehensively discussed in this review.
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Atiya, Ghalib A., Abdulqadier H. Al khazraji, and Sahar H. Mourad. "The Effect of the Polymer Type in the Three-Phases Fischer-Tropsch Synthesis Catalyzed by suspended Iron Nanocatalysts." Mediterranean Journal of Chemistry 9, no. 5 (December 2, 2019): 363–70. http://dx.doi.org/10.13171/mjc01912021046gaa.
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Fischer-Tropsch synthesis (FTS) was conducted over paraffin-iron catalysts of three phases system with synthetic polymers that contains different compositions. The suspended iron nanocatalyst was introduced into the slurry reactors Fischer-Tropsch with range temperature (220-320)oC at 2.0 MPa, the atomic ratio contains: 100Fe/100 Paraffin/10 wt% polymer. The study of phase, structure and morphology of the nanocatalyst using x-ray diffraction (XRD) and atomic force microscope (AFM) techniques confirmed that there are two phases of iron oxides Fe3O4 and δ-FeOOH are existed. Maximum conversion of CO to yields of total liquid hydrocarbons that obtained was 74% and 62 g/m3 of FTS over the catalyst Fe-Paraffin/ Polyethylene glycol (Fe-P/PEG) compared to Fe-Paraffin/ Polyethylene terephthalate (Fe-P/PET) and Fe-Paraffin/polycarbonate (Fe-P/PC) systems. The results shows that the polymer type and their structure as well as preparation time of the iron nanocatalysts have high influence on the particle size value. A selectivity of 65% of syngas converted C5+ liquid hydrocarbons achieved using (Fe-P/PEG) catalyst.
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Chen, Tao, Yuwei Zhang, and Weilin Xu. "Single-Molecule Nanocatalysis Reveals Catalytic Activation Energy of Single Nanocatalysts." Journal of the American Chemical Society 138, no. 38 (September 14, 2016): 12414–21. http://dx.doi.org/10.1021/jacs.6b05600.
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Shaheen, Saman, Iqra Sadiq, Syed Asim Ali, and Tokeer Ahmad. "Bismuth-Based Multi-Component Heterostructured Nanocatalysts for Hydrogen Generation." Catalysts 13, no. 2 (January 28, 2023): 295. http://dx.doi.org/10.3390/catal13020295.
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Developing a unique catalytic system with enhanced activity is the topmost priority in the science of H2 energy to reduce costs in large-scale applications, such as automobiles and domestic sectors. Researchers are striving to design an effective catalytic system capable of significantly accelerating H2 production efficiency through green pathways, such as photochemical, electrochemical, and photoelectrochemical routes. Bi-based nanocatalysts are relatively cost-effective and environmentally benign materials which possess advanced optoelectronic properties. However, these nanocatalysts suffer back recombination reactions during photochemical and photoelectrochemical operations which impede their catalytic efficiency. However, heterojunction formation allows the separation of electron–hole pairs to avoid recombination via interfacial charge transfer. Thus, synergetic effects between the Bi-based heterostructured nanocatalysts largely improves the course of H2 generation. Here, we propose the systematic review of Bi-based heterostructured nanocatalysts, highlighting an in-depth discussion of various exceptional heterostructures, such as TiO2/BiWO6, BiWO6/Bi2S3, Bi2WO6/BiVO4, Bi2O3/Bi2WO6, ZnIn2S4/BiVO4, Bi2O3/Bi2MoO6, etc. The reviewed heterostructures exhibit excellent H2 evolution efficiency, ascribed to their higher stability, more exposed active sites, controlled morphology, and remarkable band-gap tunability. We adopted a slightly different approach for reviewing Bi-based heterostructures, compiling them according to their applicability in H2 energy and discussing challenges, prospects, and guidance to develop better and more efficient nanocatalytic systems.
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Qian, Xiaoqin, Jun Zhang, Zi Gu, and Yu Chen. "Nanocatalysts-augmented Fenton chemical reaction for nanocatalytic tumor therapy." Biomaterials 211 (August 2019): 1–13. http://dx.doi.org/10.1016/j.biomaterials.2019.04.023.
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Abdul Hamza, Taha Mahdi. "Review on Applications of Nanocatalyst in Refineries and petrochemicals." Journal of Petroleum Research and Studies 7, no. 2 (May 6, 2021): 96–107. http://dx.doi.org/10.52716/jprs.v7i2.191.
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In the nanoscience where all the devices and technologies are going to smaller in size with improved properties, catalysis is an important field of application. In recent years, nanocatalysis has become more emerging field of science due to its high activity, selectivity and productivity. In this mini-review, we are trying to summarize data reported in literature for application of nano sized catalyst in Refineries and petrochemicals industries. By decreasing the size of the catalyst, advantages such as large surface area would be exposed to the reactant. Main applications of nanocatalysts in steam reforming, bio diesel production, and several other point of application are discussed here in detail.
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Brault, Pascal. "Multiscale Molecular Dynamics Simulations of Fuel Cell Nanocatalyst Plasma Sputtering Growth and Deposition." Energies 13, no. 14 (July 11, 2020): 3584. http://dx.doi.org/10.3390/en13143584.
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Molecular dynamics simulations (MDs) are carried out for predicting platinum Proton Exchange Membrane (PEM) fuel cell nanocatalyst growth on a model carbon electrode. The aim is to provide a one-shot simulation of the entire multistep process of deposition in the context of plasma sputtering, from sputtering of the target catalyst/transport to the electrode substrate/deposition on the porous electrode. The plasma processing reactor is reduced to nanoscale dimensions for tractable MDs using scale reduction of the plasma phase and requesting identical collision numbers in experiments and the simulation box. The present simulations reproduce the role of plasma pressure for the plasma phase growth of nanocatalysts (here, platinum).
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Fierascu, Ortan, Avramescu, and Fierascu. "Phyto-Nanocatalysts: Green Synthesis, Characterization, and Applications." Molecules 24, no. 19 (September 20, 2019): 3418. http://dx.doi.org/10.3390/molecules24193418.
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Catalysis represents the cornerstone of chemistry, since catalytic processes are ubiquitous in almost all chemical processes developed for obtaining consumer goods. Nanocatalysis represents nowadays an innovative approach to obtain better properties for the catalysts: stable activity, good selectivity, easy to recover, and the possibility to be reused. Over the last few years, for the obtaining of new catalysts, classical methods—based on potential hazardous reagents—have been replaced with new methods emerged by replacing those reagents with plant extracts obtained in different conditions. Due to being diversified in morphology and chemical composition, these materials have different properties and applications, representing a promising area of research. In this context, the present review focuses on the metallic nanocatalysts’ importance, different methods of synthesis with emphasis to the natural compounds used as support, characterization techniques, parameters involved in tailoring the composition, size and shape of nanoparticles and applications in catalysis. This review presents some examples of green nanocatalysts, grouped considering their nature (mono- and bi-metallic nanoparticles, metallic oxides, sulfides, chlorides, and other complex catalysts).
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Boltersdorf, Jonathan, Gregory Forcherio, Asher Leff, Behnaz Ostovar, Yiyu Cai, Stephan Link, and David R. Baker. "Photoelectrochemical Hydrocarbon Oxidation Augmented By Plasmonic Nanostructures." ECS Meeting Abstracts MA2022-01, no. 50 (July 7, 2022): 2113. http://dx.doi.org/10.1149/ma2022-01502113mtgabs.
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Solar energy can be absorbed via surface plasmon resonance (SPR) to promote excitation of energetic, or “hot”, charge carriers that can be locally transferred or thermally dissipated to augment photocatalytic processes. The “hot” carriers can selectively drive energy-intensive photoelectrochemical reactions at low temperatures by activating adsorbed reactants and accelerating surface kinetics. Plasmonically-sensitized nanocatalysts were investigated for their photocatalytic and photoelectrochemical oxidation of ethanol, with an emphasis on carbon-carbon bond cleavage, under solar simulated-light irradiation. Material approaches included the (i) SPR-functionalization of a traditional metal oxide semiconductor (TiO2) and (ii) bimetallic nanocatalysts composed of epitaxially photodeposited catalytic Pd at targeted locations on plasmonic Au nanorods. Results are correlated with nanocatalyst morphology, composition, and homogeneity to maintain SPR-induced charge separation and mitigate carbon monoxide poisoning. Ensemble photoelectrochemical measurements were complimented with single-particle dark-field scattering and photoluminescence spectroscopies to understand the extraction and utilization of SPR-excited “hot” carriers. Ethanol oxidation was achieved, yielding a solar-driven method for low temperature, complete photo-oxidation of complex hydrocarbons via plasmonic photocatalysis.
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Guo, Ruihua, Na An, Yarong Huang, Lili Guan, Guofang Zhang, Guofu Zhu, and Zhaogang Liu. "One-Pot Synthesis of Pt High Index Facets Catalysts for Electrocatalytic Oxidation of Ethanol." Nanomaterials 12, no. 24 (December 14, 2022): 4451. http://dx.doi.org/10.3390/nano12244451.
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Direct ethanol fuel cell (DEFC) has attracted wide attention due to its wide range of fuel sources, cleanliness, and high efficiency. However, the problems of low catalytic efficiency and poor catalyst stability still exist in DEFC catalysts, which restrict its rapid development. With chloroplatinic acid (H2PtCl6·6H2O) as the precursor, Polyvinylpyrrolidone (PVP) plays the role of surfactant, stabilizer, and reducing agent in the experiment. Glycine is the surface control agent and co-reducing agent. Pt high-index facets nanocatalyst was prepared with the one-pot hydrothermal method by adjusting the amount of PVP and glycine. X-Ray Diffraction (XRD), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize the micro-structure of the nanocatalyst, and the influence of PVP and glycine on the synthesis of high-index facets catalyst was studied. The electrocatalytic performance of the catalyst was tested with an electrochemical workstation, and it was found that the performance of the prepared catalyst was better than that of the commercial catalyst. When the mass ratio of PVP and Pt was 50:1 and the molar ratio of glycine and Pt was 24:1, Pt nanocatalysts with {310}, {520} and {830} high exponential facets were prepared. The electrochemical test results showed that the peak current density of ethanol oxidation was 2.194 m2/g, and the steady-state current density was 0.241 mA/cm2, which was 5.7 times higher than that of commercial catalyst. The results of this paper show that due to the defects such as steps and kinks on the surface of the high-index facets, the active sites are increased, thus showing excellent electrocatalytic performance. This study provides a theoretical basis for the development and commercial application of high index facets nanocatalysts.
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Khalil, Munawar, Rendy Muhamad Iqbal, Grandprix T. M. Kadja, and Dede Djuhana. "Recent Advances on Plasmon-enhanced Titania Nanocatalysts for Photocatalytic Degradation of Organic Dyes." Journal of the Indonesian Chemical Society 3, no. 3 (December 30, 2020): 117. http://dx.doi.org/10.34311/jics.2020.03.3.117.
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In the past several years, solar-driven photocatalytic degradation of organic dyes has been considered as one of the most promising and effective ways to address water pollution issues. Nevertheless, the implementation of such technology for large scale industrial wastewater application is still hampered by the limitation in currently used photocatalysts. Recently, plasmon-enhanced titania-based nanocatalyst has emerged as one of the promising photocatalytic materials for solar-driven wastewater treatment due to its excellent activity and ability to absorb a large portion of solar radiation. Therefore, this review highlights recent progress on applying such material for the photodegradation of organic dyes. In this review, the focus is placed on several mechanisms on how the surface plasmon resonance (SPR) phenomenon could enhance the photocatalytic activity of semiconductors, such as TiO2. Furthermore, the performance of several types of plasmon-enhanced titania nanocatalyst with different kinds of metal plasmonic nanoparticles, i.e., Au-TiO2, Ag-TiO2, and Pd-TiO2, is also compared and comprehensively discussed. Finally, a particular emphasis is also given to highlight the nanocatalysts' kinetics in facilitating the photocatalytic degradation of different types of organic dyes.
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Khalid Ouzaouit and Abdelhay Aboulaich. "Nd-Doped Barium Cerate Nano-Sized Catalyst Converts CH4 into CO2 at Lower Temperature Compared to Noble Metal-Based Pd/Al2O3 Catalyst." Journal of Environmental Nanotechnology 10, no. 3 (September 24, 2021): 01–08. http://dx.doi.org/10.13074/jent.2021.09.213439.
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The present paper describes the synthesis and first application of Nd-doped BaCeO3 nanoparticles as catalyst for the catalytic oxidation of methane (CH4) into CO2. Nd-doped barium cerate BaCeO3 nanoparticles, with the formula BaNdxCe(1-x)O3, have been prepared using a simple sol gel method starting from acetate precursors. The as-prepared nanoparticles have been fully characterized by XRD, TEM, HRTEM and specific surface area measurement. Results confirmed the formation of highly crystallized nano-sized particles with small crystallite size. In-situ FTIR spectroscopy was used to study the catalytic conversion of methane (CH4) into CO2 in the presence of the as-prepared Nd-doped BaCeO3 nanocatalyst. The catalytic properties of such nanocatalysts have been discussed and correlated to Nd-doping rate, crystallite diameter, and specific surface area of the materials. Excellent catalytic properties have been obtained with BaNd0.05Ce0.95O3, such as, superior conversion efficiency, longer catalysis lifetime and lower activation temperature compared to un-doped BaCeO3 catalyst. Interestingly, it was found that BaNd0.05Ce0.95O3 nanocatalyst successfully converts the totality of CH4 present in a mixture of CH4-Air into CO2 at much lower temperature compared to the conventional Pd/Al2O3 catalyst.