Articoli di riviste: "Non noble transition metal"

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Caffrey, Andrew P., Patrick E. Hopkins, J. Michael Klopf e Pamela M. Norris. "Thin Film Non-Noble Transition Metal Thermophysical Properties". Microscale Thermophysical Engineering 9, n. 4 (ottobre 2005): 365–77. http://dx.doi.org/10.1080/10893950500357970.

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Chen, Ying, Yuling Hu e Gongke Li. "A Review on Non-Noble Metal Substrates for Surface-Enhanced Raman Scattering Detection". Chemosensors 11, n. 8 (1 agosto 2023): 427. http://dx.doi.org/10.3390/chemosensors11080427.

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Surface-enhanced Raman scattering (SERS), a powerful spectroscopic technique owing to its abundant vibrational fingerprints, has been widely employed for the assay of analytes. It is generally considered that one of the critical factors determining the SERS performance is the property of the substrate materials. Apart from noble metal substrates, non-noble metal nanostructured materials, as emerging new substrates, have been extensively studied for SERS research by virtue of their superior biocompatibility, good chemical stability, outstanding selectivity, and unique physicochemical properties such as adjustable band structure and carrier concentration. Herein, in this review, we summarized the research on the analytical application of non-noble metal SERS substrates from three aspects. Firstly, we started with an introduction to the possible enhancement mechanism of non-noble metal substrates. Then, as a guideline for substrates design, several main types of materials, including carbon nanomaterials, transition metal dichalcogenides (TMDs), metal oxides, metal-organic frameworks (MOFs), transition metal carbides and nitrides (MXenes), and conjugated polymers were discussed. Finally, we especially emphasized their analytical application, such as the detection of pollutants and biomarkers. Moreover, the challenges and attractive research prospects of non-noble metal SERS substrates in practical application were proposed. This work may arouse more awareness of the practical application of the non-noble metal material-based SERS substrates, especially for bioanalysis.

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Guo, Xiaotian, Guangxun Zhang, Qing Li, Huaiguo Xue e Huan Pang. "Non-noble metal-transition metal oxide materials for electrochemical energy storage". Energy Storage Materials 15 (novembre 2018): 171–201. http://dx.doi.org/10.1016/j.ensm.2018.04.002.

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Mantella, Valeria, Laia Castilla-Amorós e Raffaella Buonsanti. "Shaping non-noble metal nanocrystals via colloidal chemistry". Chemical Science 11, n. 42 (2020): 11394–403. http://dx.doi.org/10.1039/d0sc03663c.

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This minireview describes the state-of-the-art of shape-controlled nanocrystals of third raw transition metals and discusses future directions to advance their synthetic development, which is important for many applications.

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Niu, Xiangheng, Xin Li, Jianming Pan, Yanfang He, Fengxian Qiu e Yongsheng Yan. "Recent advances in non-enzymatic electrochemical glucose sensors based on non-precious transition metal materials: opportunities and challenges". RSC Advances 6, n. 88 (2016): 84893–905. http://dx.doi.org/10.1039/c6ra12506a.

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Alhassan, Mansur, Mahadi Bin Bahari, Abdelrahman Hamad Khalifa Owgi e Thuan Van Tran. "Non-noble metal catalysts for dry reforming of methane: Challenges, opportunities, and future directions". E3S Web of Conferences 516 (2024): 02002. http://dx.doi.org/10.1051/e3sconf/202451602002.

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The utilization of non-noble metal catalysts for the dry reforming of methane (DRM) has gained significant attention in recent years due to the increasing demand for clean and sustainable energy sources. DRM involves the conversion of methane (CH4) and carbon (IV) oxide (CO2) into synthesis gas (syngas), a valuable mixture of hydrogen (H2) and carbon monoxide (CO). Commercialization of non-noble metal catalysts for this reaction presents several challenges that must be addressed to achieve practical implementation. This short review discusses the challenges, opportunities, and future directions of non-noble metal catalysts for DRM. First, the limitations associated with the intrinsic activity and stability of non-noble metals, such as nickel, cobalt, and iron, are explored. Enhancing catalyst performance through compositional modifications, the incorporation of promoters and supports, are ways to overcome these challenges. Directions that hold promise for advancing non-noble metal catalysts in DRM, including the advanced exploration of bimetallic catalysts for synergistic effects, and the integration of non-noble metals into novel catalytic systems, were among the future proposals, while non-noble metal catalysts have the potential to revolutionize the production of syngas and contribute significantly to the transition towards sustainable energy solutions.

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Zhang, Wenqing, Juan Wang, Lanling Zhao, Junru Wang e Mingwen Zhao. "Transition-metal monochalcogenide nanowires: highly efficient bi-functional catalysts for the oxygen evolution/reduction reactions". Nanoscale 12, n. 24 (2020): 12883–90. http://dx.doi.org/10.1039/d0nr01148g.

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We demonstrate the transition-metal monochalcogenide nanowires as efficient bi-functional OER/ORR catalysts competitive with noble catalysts, paving a way for the development of stable, low-cost and high-active non-noble electrocatalysts.

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Nkabinde, Siyabonga S., Patrick V. Mwonga, Siyasanga Mpelane, Zakhele B. Ndala, Tshwarela Kolokoto, Ndivhuwo P. Shumbula, Obakeng Nchoe et al. "Phase-dependent electrocatalytic activity of colloidally synthesized WP and α-WP2 electrocatalysts for hydrogen evolution reaction". New Journal of Chemistry 45, n. 34 (2021): 15594–606. http://dx.doi.org/10.1039/d1nj00927c.

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Jin, Xinxin, Yu Jiang, Qi Hu, Shaohua Zhang, Qike Jiang, Li Chen, Ling Xu, Yan Xie e Jiahui Huang. "Highly efficient electrocatalysts with CoO/CoFe2O4 composites embedded within N-doped porous carbon materials prepared by hard-template method for oxygen reduction reaction". RSC Advances 7, n. 89 (2017): 56375–81. http://dx.doi.org/10.1039/c7ra09517a.

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Low-cost dual transition metal (Fe and Co) based non-noble metal electrocatalysts (NNMEs) with large surface area and porous structure boost oxygen reduction reaction (ORR) performance in alkaline solution.

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Masferrer-Rius, Eduard, e Robertus J. M. Klein Gebbink. "Non-Noble Metal Aromatic Oxidation Catalysis: From Metalloenzymes to Synthetic Complexes". Catalysts 13, n. 4 (19 aprile 2023): 773. http://dx.doi.org/10.3390/catal13040773.

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The development of selective aromatic oxidation catalysts based on non-noble metals has emerged over the last decades, mainly due to the importance of phenol products as intermediates for the generation of pharmaceuticals or functional polymers. In nature, metalloenzymes can perform a wide variety of oxidative processes using molecular oxygen, including arene oxidations. However, the implementation of such enzymes in the chemical industry remains challenging. In this context, chemists have tried to mimic nature and design synthetic non-noble metal catalysts inspired by these enzymes. This review aims at providing a general overview of aromatic oxidation reactions catalyzed by metalloenzymes as well as synthetic first-row transition-metal complexes as homogeneous catalysts. The enzymes and complexes discussed in this review have been classified based on the transition-metal ion present in their active site, i.e., iron, copper, nickel, and manganese. The main points of discussion focus on enzyme structure and function, catalyst design, mechanisms of operation in terms of oxidant activation and substrate oxidation, and substrate scope.

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Makvandi, Pooyan, Atefeh Zarepour, Xuanqi Zheng, Tarun Agarwal, Matineh Ghomi, Rossella Sartorius, Ehsan Nazarzadeh Zare et al. "Non-spherical nanostructures in nanomedicine: From noble metal nanorods to transition metal dichalcogenide nanosheets". Applied Materials Today 24 (settembre 2021): 101107. http://dx.doi.org/10.1016/j.apmt.2021.101107.

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Park, Hyeonji, Kyeongwon Han, Hyungjin Kim, Jeongeun Song, Yuri Ko e Yukwon Jeon. "Optimization of Oxygen Reduction Activity Via Transition Metal-Oxide Based Composite Electrodes in Acidic Medium". ECS Meeting Abstracts MA2024-02, n. 25 (22 novembre 2024): 2035. https://doi.org/10.1149/ma2024-02252035mtgabs.

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Global warming has occurred due to the usage of fossil fuels and greenhouse gas emissions. Therefore, a change in the energy paradigm can overcome the problems of global warming and air pollution and provide new energy to humanity continuously. Fuel cells are an eco-friendly system that utilizes the electricity generated during the process of producing water from hydrogen fuel. In general, 20 wt% Pt/C is used as the commercial catalyst for polymer electrolyte fuel cells (PEFCs), but challenges remain to solve such as cost and durability. In PEFCs, oxygen reduction reaction (ORR) is an important key as a rate-determining step (RDS) to react the overall reaction. Therefore, it is necessary to develop efficient materials (electrode, membrane, cell, etc.) for improving RDS. Recently, transition metal oxide (TMO) composite electrodes have gained interest in the electrochemical fields. Especially, nickel, cobalt, iron-based oxides are promising materials as non-noble metal electrocatalysts due to their high electric conductivity and various oxidation state. The purpose in this research is to improve ORR performance by controlling active sites and electric conductivity using low amount of noble metals on transition metal doped oxides for the use at the electrode. We have developed composite oxide electrodes with noble-transition metal alloy using solid-state methods. Small amount of noble metal can be alloyed with transition metal to form appropriate oxygen binding energy for oxygen adsorption and desorption, which can improve ORR activity. To check the catalytic activity, cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were analyzed using a rotating disk electrode, and it was found that the noble metal-transition metal alloy oxide composite electrode was effective in enhancing the ORR kinetics. Additionally, the strong interaction between the alloy nanoparticles and oxide support surface enhances chemical stability when used in harsh environments such as acidic media. Furthermore, based on the previous ORR data, we fabricated membrane electrode assembly (MEA) using developed catalysts and confirmed their potential for PEFCs applications.

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Du, Meng, Lingling Guo, Hongju Ren, Xin Tao, Yunan Li, Bing Nan, Rui Si, Chongqi Chen e Lina Li. "Non-Noble FeCrOx Bimetallic Nanoparticles for Efficient NH3 Decomposition". Nanomaterials 13, n. 7 (5 aprile 2023): 1280. http://dx.doi.org/10.3390/nano13071280.

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Ammonia has the advantages of being easy to liquefy, easy to store, and having a high hydrogen content of 17.3 wt%, which can be produced without COx through an ammonia decomposition using an appropriate catalyst. In this paper, a series of FeCr bimetallic oxide nanocatalysts with a uniform morphology and regulated composition were synthesized by the urea two-step hydrolysis method, which exhibited the high-performance decomposition of ammonia. The effects of different FeCr metal ratios on the catalyst particle size, morphology, and crystal phase were investigated. The Fe0.75Cr0.25 sample exhibited the highest catalytic activity, with an ammonia conversion of nearly 100% at 650 °C. The dual metal catalysts clearly outperformed the single metal samples in terms of their catalytic performance. Besides XRD, XPS, and SEM being used as the means of the conventional characterization, the local structural changes of the FeCr metal oxide catalysts in the catalytic ammonia decomposition were investigated by XAFS. It was determined that the Fe metal and FeNx of the bcc structure were the active species of the ammonia-decomposing catalyst. The addition of Cr successfully prevented the Fe from sintering at high temperatures, which is more favorable for the formation of stable metal nitrides, promoting the continuous decomposition of ammonia and improving the decomposition activity of the ammonia. This work reveals the internal relationship between the phase and structural changes and their catalytic activity, identifies the active catalytic phase, thus guiding the design and synthesis of catalysts for ammonia decomposition, and excavates the application value of transition-metal-based nanocomposites in industrial catalysis.

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Sheetal, Pushkar Mehara e Pralay Das. "Methanol as a greener C1 synthon under non-noble transition metal-catalyzed conditions". Coordination Chemistry Reviews 475 (gennaio 2023): 214851. http://dx.doi.org/10.1016/j.ccr.2022.214851.

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Amin, R. S., Amani E. Fetohi, D. Z. Khater, Jin Lin, Yanzhong Wang, Chao Wang e K. M. El-Khatib. "Selenium-transition metal supported on a mixture of reduced graphene oxide and silica template for water splitting". RSC Advances 13, n. 23 (2023): 15856–71. http://dx.doi.org/10.1039/d3ra01945d.

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Exploration of economical, highly efficient, and environment friendly non-noble-metal-based electrocatalysts is necessary for hydrogen and oxygen evolution reactions (HER and OER) but challenging for cost-effective water splitting.

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Hao, Zhuo, Yangyang Ma, Yisong Chen, Pei Fu e Pengyu Wang. "Non-Noble Metal Catalysts in Cathodic Oxygen Reduction Reaction of Proton Exchange Membrane Fuel Cells: Recent Advances". Nanomaterials 12, n. 19 (24 settembre 2022): 3331. http://dx.doi.org/10.3390/nano12193331.

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The oxygen reduction reaction (ORR) is one of the crucial energy conversion reactions in proton exchange membrane fuel cells (PEMFCs). Low price and remarkable catalyst performance are very important for the cathode ORR of PEMFCs. Among the various explored ORR catalysts, non-noble metals (transition metal: Fe, Co, Mn, etc.) and N co-doped C (M–N–C) ORR catalysts have drawn increasing attention due to the abundance of these resources and their low price. In this paper, the recent advances of single-atom catalysts (SACs) and double-atom catalysts (DACs) in the cathode ORR of PEMFCs is reviewed systematically, with emphasis on the synthesis methods and ORR performance of the catalysts. Finally, challenges and prospects are provided for further advancing non-noble metal catalysts in PEMFCs.

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Xie, Song, Hao Dong, Xiang Peng e Paul K. Chu. "Non-precious Electrocatalysts for the Hydrogen Evolution Reaction". Innovation Discovery 1, n. 2 (17 maggio 2024): 11. http://dx.doi.org/10.53964/id.2024011.

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The development of non-precious metal-based catalysts for the hydrogen evolution reaction (HER) is a promising research area with the potential to advance water electrolysis and enable the widespread use of hydrogen as a clean energy source. While noble metals like Pt and Pd exhibit excellent HER activity, their limited availability and high cost present significant challenges. Non-precious transition metals such as Fe, Co, and Ni have emerged as alternative catalyst materials due to their natural abundance. However, these metals often encounter obstacles related to their hydrogen adsorption behavior. This commentary highlights the various strategies employed to optimize the electronic structures of non-precious metal-based catalysts to enhance the HER performance. The outlook of non-precious metal-based catalysts is bright, with ongoing and future research activities mainly focusing on improving their properties, integrating these catalysts into commercial water electrolysis systems, and improving the scalability for large-scale hydrogen production. The development of high-performance non-precious metal-based catalysts for HER is crucial to future sustainable and efficient hydrogen production in the transition from fossil fuels to clean energy.

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Li, Yang, Yao Liu, Jinhui Zhang, Dashuai Wang e Jing Xu. "Rational Design of Non-Noble Metal Single-Atom Catalysts in Lithium–Sulfur Batteries through First Principles Calculations". Nanomaterials 14, n. 8 (17 aprile 2024): 692. http://dx.doi.org/10.3390/nano14080692.

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Lithium–sulfur (Li–S) batteries with a high theoretical energy density of 2600 Wh·kg−1 are hindered by challenges such as low S conductivity, the polysulfide shuttle effect, low S reduction conversion rate, and sluggish Li2S oxidation kinetics. Herein, single-atom non-noble metal catalysts (SACs) loaded on two-dimensional (2D) vanadium disulfide (VS2) as the potential host materials for the cathode in Li–S batteries were investigated systematically by using first-principles calculations. Based on the comparisons of structural stability, the ability to immobilize sulfur, electrochemical reactivity, and the kinetics of Li2S oxidation decomposition between these non-noble metal catalysts and noble metal candidates, Nb@VS2 and Ta@VS2 were identified as the potential candidates of SACs with the decomposition energy barriers for Li2S of 0.395 eV (Nb@VS2) and of 0.162 eV (Ta@VS2), respectively. This study also identified an exothermic reaction for Nb@VS2 and the Gibbs free energy of 0.218 eV for Ta@VS2. Furthermore, the adsorption and catalytic mechanisms of the VS2-based SACs in the reactions were elucidated, presenting a universal case demonstrating the use of unconventional graphene-based SACs in Li–S batteries. This study presents a universal surface regulation strategy for transition metal dichalcogenides to enhance their performance as host materials in Li–S batteries.

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Moni, Snehasis, e Bhaskar Mondal. "Correlation between Key Steps and Hydricity in CO2 Hydrogenation Catalysed by Non-Noble Metal PNP-Pincer Complexes". Catalysts 13, n. 3 (15 marzo 2023): 592. http://dx.doi.org/10.3390/catal13030592.

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Transition metal-catalysed homogeneous hydrogenation of CO2 to formate or formic acid has emerged as an appealing strategy for the reduction of CO2 into value-added chemicals. Since the state-of-the-art catalysts in this realm are primarily based on expensive precious metals and require demanding reaction conditions, the design and development of economically viable non-noble metal catalysts are in great demand. Herein, we exploit the thermodynamic correlation between the crucial reaction steps of CO2 hydrogenation, that is, base-promoted H2-splitting and hydride transfer to CO2 as a guide to estimate the catalytic efficiency of non-noble metal complexes possessing a ligand backbone containing a secondary amine as an “internal base”. A set of three non-noble metal complexes, one bearing tri-coordinated PNP-pincer (1Mn) and the other two based on tetra-coordinated PNPN-pincer (2Mn and 3Fe), have been investigated in this study. The computational mechanistic investigation establishes the role of the “internal” amine base in heterolytically splitting the metal-bound H2, a critical step for CO2 hydrogenation. Furthermore, the thermodynamic correlation between the hydricity (ΔGH−°) of the in situ generated metal-hydride species and the free energy barrier of the two crucial steps could provide an optimal hydricity value for efficient catalytic activity. Based on the computational estimation of the optimal hydricity value, the tri-coordinated PNP-pincer complex 1Mn appears to be the most efficient among the three, with the other two tetra-coordinated PNPN-pincer complexes, 2Mn and 3Fe, showing promising hydricity values. Overall, this study demonstrates how the crucial thermodynamic and kinetic parameters for pincer-based complexes possessing an “internal base” can be correlated for the prediction of novel non-noble metal-based catalysts for CO2 hydrogenation.

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Yang, Yibin, Yingqing Ou, Yang Yang, Xijun Wei, Di Gao, Lin Yang, Yuli Xiong, Hongmei Dong, Peng Xiao e Yunhuai Zhang. "Modulated transition metal–oxygen covalency in the octahedral sites of CoFe layered double hydroxides with vanadium doping leading to highly efficient electrocatalysts". Nanoscale 11, n. 48 (2019): 23296–303. http://dx.doi.org/10.1039/c9nr08795h.

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Yan, Liang, Bing Zhang, Shangyou Wu e Jianlin Yu. "A general approach to the synthesis of transition metal phosphide nanoarrays on MXene nanosheets for pH-universal hydrogen evolution and alkaline overall water splitting". Journal of Materials Chemistry A 8, n. 28 (2020): 14234–42. http://dx.doi.org/10.1039/d0ta05189f.

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Budweg, Svenja, Kathrin Junge e Matthias Beller. "Catalytic oxidations by dehydrogenation of alkanes, alcohols and amines with defined (non)-noble metal pincer complexes". Catalysis Science & Technology 10, n. 12 (2020): 3825–42. http://dx.doi.org/10.1039/d0cy00699h.

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Zhou, Shanhu, e Jun Hu. "Enhancing perpendicular magnetocrystalline anisotropy in Fe ultrathin films by non-noble transition-metal substrate". International Journal of Modern Physics C 31, n. 09 (27 agosto 2020): 2050134. http://dx.doi.org/10.1142/s012918312050134x.

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Based on first-principles calculations, we studied the magnetic properties of ultrathin Fe film on a nonmagnetic substrate Ta(001). We found that the perpendicular magnetocrystalline anisotropy (PMA) of Fe/Ta(001) system with only one or two Fe atomic layer(s) can be enhanced significantly, and the corresponding magnetocrystalline anisotropy energy is enlarged tos about 3 times of that in pure ultrathin Fe film. Analysis of electronic properties demonstrates that the magnetic proximity effect at the Fe/Ta interface plays an important role in the enhancement of the PMA. Alternative arrangement of Ta and Fe layers with more Fe/Ta interfaces may further strengthen the PMA.

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Ogo, Shuhei, e Yasushi Sekine. "Recent progress in ethanol steam reforming using non-noble transition metal catalysts: A review". Fuel Processing Technology 199 (marzo 2020): 106238. http://dx.doi.org/10.1016/j.fuproc.2019.106238.

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Wang, Yijing. "Rational Design of HighPerformance M-N-C Single Atom Catalysts". Journal of Mineral and Material Science (JMMS) 4, n. 5 (4 dicembre 2023): 1–3. http://dx.doi.org/10.54026/jmms/1074.

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High-performance electrocatalysts are required because the sluggish kinetics of Oxygen Reduction Reaction (ORR) at the cathode in either Fuel Cell (FC) or Metal-Air Battery (MAB). The current most effective ORR catalysts are noble Pt-group metals, whose high price and low abundance severely hamper the widespread application of FC and MAB. Dispersively non-noble transition metal coordinated with nitrogen atoms doped in carbon nanomaterials (M-N-C) Single Atom Catalysts (SACs) have been considered as the most promising catalysts for the ORR. Here, the effect of typical morphology on the activity and stability of SACs was discussed firstly. Moreover, the effect of metal type, coordination nitrogen number, heteroatom decoration on the central metal atom were discussed. Based on the rate determining step (RDS), we propose the ideal characters that high-performance SACs should possess.

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Lozano, Luis A., Betina M. C. Faroldi, María A. Ulla e Juan M. Zamaro. "Metal–Organic Framework-Based Sustainable Nanocatalysts for CO Oxidation". Nanomaterials 10, n. 1 (17 gennaio 2020): 165. http://dx.doi.org/10.3390/nano10010165.

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The development of new catalytic nanomaterials following sustainability criteria both in their composition and in their synthesis process is a topic of great current interest. The purpose of this work was to investigate the preparation of nanocatalysts derived from the zirconium metal–organic framework UiO-66 obtained under friendly conditions and supporting dispersed species of non-noble transition elements such as Cu, Co, and Fe, incorporated through a simple incipient wetness impregnation technique. The physicochemical properties of the synthesized solids were studied through several characterization techniques and then they were investigated in reactions of relevance for environmental pollution control, such as the oxidation of carbon monoxide in air and in hydrogen-rich streams (COProx). By controlling the atmospheres and pretreatment temperatures, it was possible to obtain active catalysts for the reactions under study, consisting of Cu-based UiO-66-, bimetallic CuCo–UiO-66-, and CuFe–UiO-6-derived materials. These solids represent new alternatives of nanostructured catalysts based on highly dispersed non-noble active metals.

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Pan, Jing, Rui Wang, Xiaoyong Xu, Jingguo Hu e Liang Ma. "Transition metal doping activated basal-plane catalytic activity of two-dimensional 1T’-ReS2 for hydrogen evolution reaction: a first-principles calculation study". Nanoscale 11, n. 21 (2019): 10402–9. http://dx.doi.org/10.1039/c9nr00997c.

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Non-noble transition metals Mo and Cr doping greatly enhances the basal-plane catalytic activity of two-dimensional 1T′-ReS₂ for hydrogen evolution reaction as comparable with those of Pt-doping.

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Liu, Taizhe. "Performance of recent transition metal cocatalysts under hydrogen evolution reaction". Applied and Computational Engineering 7, n. 1 (21 luglio 2023): 136–46. http://dx.doi.org/10.54254/2755-2721/7/20230407.

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In case clean and renewable energy on earth is urgently needed, converting solar energy into hydrogen is applied. Due to its high efficiency and low cost, photoelectrochemical water splitting (PEC) has become a popular strategy. To achieve this, non-noble metal electrocatalysts as cocatalysts are used to enhance the performance of PEC water splitting. In this review, the recent procedure of the synthesis, performance measurements, and the result of MoSx, TiO2/NiOx, Pt/TiO2/InAs NWs, and CoS are introduced. These materials show a fit onset potential, good current density, and small charge transfer resistance for hydrogen evolution reaction (HER). Compared with TiO2/NiOx, Pt/TiO2/InAs NWs, and CoS, MoSx is the only stable under acidic conditions. Some suggestions for future research on transition metal-based electrocatalysts are also provided.

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Redina, Elena, Olga Tkachenko e Tapio Salmi. "Recent Advances in C5 and C6 Sugar Alcohol Synthesis by Hydrogenation of Monosaccharides and Cellulose Hydrolytic Hydrogenation over Non-Noble Metal Catalysts". Molecules 27, n. 4 (17 febbraio 2022): 1353. http://dx.doi.org/10.3390/molecules27041353.

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A new reality of the 21st century is the transition to a new type of economy and energy concepts characterized by the replacement of existing petrochemical routes to a bio-based circular economy. The needs for new strategies in obtaining basic products from bio-based resources with minimum CO2 traces has become mandatory. In this review, recent trends in the conversion of biomass-derived molecules, such as simple monomeric sugars and cellulose, to industrially important C5 and C6 sugar alcohols on heterogeneous catalysts based on non-noble metals are discussed focusing on the influence of catalyst structures and reaction conditions used on the substrate conversion and product selectivity. The challenges and prominent ideas are suggested for the further development of catalytic hydrogenation of naturally abundant carbohydrates to value-added chemicals on non-noble metal catalysts.

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Song, Meixiu, Yanhui Song, Wenbo Sha, Bingshe Xu, Junjie Guo e Yucheng Wu. "Recent Advances in Non-Precious Transition Metal/Nitrogen-doped Carbon for Oxygen Reduction Electrocatalysts in PEMFCs". Catalysts 10, n. 1 (20 gennaio 2020): 141. http://dx.doi.org/10.3390/catal10010141.

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The proton exchange membrane fuel cells (PEMFCs) have been considered as promising future energy conversion devices, and have attracted immense scientific attention due to their high efficiency and environmental friendliness. Nevertheless, the practical application of PEMFCs has been seriously restricted by high cost, low earth abundance and the poor poisoning tolerance of the precious Pt-based oxygen reduction reaction (ORR) catalysts. Noble-metal-free transition metal/nitrogen-doped carbon (M–NxC) catalysts have been proven as one of the most promising substitutes for precious metal catalysts, due to their low costs and high catalytic performance. In this review, we summarize the development of M–NxC catalysts, including the previous non-pyrolyzed and pyrolyzed transition metal macrocyclic compounds, and recent developed M–NxC catalysts, among which the Fe–NxC and Co–NxC catalysts have gained our special attention. The possible catalytic active sites of M–NxC catalysts towards the ORR are also analyzed here. This review aims to provide some guidelines towards the design and structural regulation of non-precious M–NxC catalysts via identifying real active sites, and thus, enhancing their ORR electrocatalytic performance.

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Perović, Klara, Silvia Morović, Ante Jukić e Krešimir Košutić. "Alternative to Conventional Solutions in the Development of Membranes and Hydrogen Evolution Electrocatalysts for Application in Proton Exchange Membrane Water Electrolysis: A Review". Materials 16, n. 18 (20 settembre 2023): 6319. http://dx.doi.org/10.3390/ma16186319.

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Proton exchange membrane water electrolysis (PEMWE) represents promising technology for the generation of high-purity hydrogen using electricity generated from renewable energy sources (solar and wind). Currently, benchmark catalysts for hydrogen evolution reactions in PEMWE are highly dispersed carbon-supported Pt-based materials. In order for this technology to be used on a large scale and be market competitive, it is highly desirable to better understand its performance and reduce the production costs associated with the use of expensive noble metal cathodes. The development of non-noble metal cathodes poses a major challenge for scientists, as their electrocatalytic activity still does not exceed the performance of the benchmark carbon-supported Pt. Therefore, many published works deal with the use of platinum group materials, but in reduced quantities (below 0.5 mg cm−2). These Pd-, Ru-, and Rh-based electrodes are highly efficient in hydrogen production and have the potential for large-scale application. Nevertheless, great progress is needed in the field of water electrolysis to improve the activity and stability of the developed catalysts, especially in the context of industrial applications. Therefore, the aim of this review is to present all the process features related to the hydrogen evolution mechanism in water electrolysis, with a focus on PEMWE, and to provide an outlook on recently developed novel electrocatalysts that could be used as cathode materials in PEMWE in the future. Non-noble metal options consisting of transition metal sulfides, phosphides, and carbides, as well as alternatives with reduced noble metals content, will be presented in detail. In addition, the paper provides a brief overview of the application of PEMWE systems at the European level and related initiatives that promote green hydrogen production.

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Kuang, Guanghua, Guangyuan Liu, Xingxing Zhang, Naihao Lu, Yiyuan Peng, Qiang Xiao e Yirong Zhou. "Directing-Group-Assisted Transition-Metal-Catalyzed Direct C–H Oxidative Annulation of Arenes with Alkynes for Facile Construction of Various Oxygen Heterocycles". Synthesis 52, n. 07 (10 febbraio 2020): 993–1006. http://dx.doi.org/10.1055/s-0039-1690816.

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The most recent advances in the construction of oxygen heterocycles by the directing-group-assisted transition-metal-catalyzed direct oxidative annulation of arenes with diverse alkynes are summarized in this review. More than 140 recent research papers and many closely related reviews are referenced in this paper. Nine different oxygen heterocycles frameworks are discussed. Several traditional transition-metal catalysts as well as some classical non-noble metals are utilized to promote the annulation. Three plausible controlling models are disclosed to clarify the excellent regioselectivity outcomes achieved in case of unsymmetrical alkyne substrates.1 Introduction2 Coumarins3 I socoumarins and Their Analogues4 2-Pyrones and Their Analogues5 Chromones and Chroman-4-ones6 Chromenes and Isochromenes7 Fused Polycyclic Oxygen Heteroaromatics8 Benzofurans, Dihydrobenzofurans, and Furans9 Phthalides and Benzofuranones10 Benzoxepines11 Conclusion

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Selvam, Praveen Kumar, Muhammad Sohail Riaz e Pau Farràs Costa. "Non-Noble Transition Metal-Based Electrocatalysts for Green Hydrogen Production from Anion Exchange Membrane (AEM) Seawater Electrolyzer". ECS Meeting Abstracts MA2023-02, n. 42 (22 dicembre 2023): 2154. http://dx.doi.org/10.1149/ma2023-02422154mtgabs.

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As water-scarce is increasing rapidly all over the world, water electrolysis might not be a practical approach for sustainable hydrogen production in the long term. Fortunately, hydrogen production from the anion exchange membrane (AEM) seawater electrolysis enables to achieve of sustainability and durability. But still, suitable electrocatalysts for hydrogen and oxygen evolution reactions in seawater are not figured out yet. Here we report non-noble transition metal-based electrocatalysts for hydrogen and oxygen evolution reaction in seawater electrolysis. The synthesized electrocatalysts were in-situ characterized in X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), Raman spectroscopy, and ex-situ characterized in linear sweep voltammetry (LSV), Chronopotentiometry, and impedance studies. Further, the electrocatalysts were investigated in a single-cell anion exchange membrane electrolyzer, and polarization curves, stability tests, and efficiency calculations were carried out. These research findings will be further investigated until attains the industrially required parameters of 1 A cm-2 at a low overpotential of 1.8 V.

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Barshick, C. M., D. H. Smith, E. Johnson, F. L. King, T. Bastug e B. Fricke. "Periodic Nature of Metal-Noble Gas Adduct Ions in Glow Discharge Mass Spectrometry". Applied Spectroscopy 49, n. 7 (luglio 1995): 885–89. http://dx.doi.org/10.1366/0003702953964840.

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The observation that ZnAr+ ion currents in a glow discharge can measure as high as 30% of those of Zn+ prompted a systematic study of metal-noble gas diatomic species. Twenty-four elements in combination with neon, argon, and krypton were included. Periodicity of behavior was observed from one row to the next with all three noble gases; periodicity was also observed as the identity of the noble gas was changed. The diatomic noble gas adduct ions of zinc, cadmium, and mercury (group 12) each displayed a concentration relative to the corresponding metal ion that was well above that of other elements in their respective rows. Investigation of the cause of this phenomenon eliminated glow discharge pressure and power conditions. Binding energies of the various species were qualitatively consistent with the observation of relative abundances of metal-noble gas diatomic ions as they varied with the identity of the noble gas, but did not explain why Zn X+, Cd X+, and Hg X+ form in what seem to be anomalously high abundance. Variations in the sputtering rates of the transition metals (Zn > Cu > Ni > Fe) are consistent with the observation that Zn X+ > Cu X+ > Ni X+ > Fe X+, the resulting increase in collision frequency (with increasing sputtering rate) is believed to account for the relative abundances of these adduct ions in the discharge.

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35

Kim, Jeong-Hyun, Jeong-Gyu Lee e Min-Jae Choi. "Progress of Metal Chalcogenides as Catalysts for Efficient Electrosynthesis of Hydrogen Peroxide". Materials 17, n. 17 (29 agosto 2024): 4277. http://dx.doi.org/10.3390/ma17174277.

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Hydrogen peroxide (H2O2) is a high-demand chemical, valued as a powerful and eco-friendly oxidant for various industrial applications. The traditional industrial method for producing H2O2, known as the anthraquinone process, is both costly and environmentally problematic. Electrochemical synthesis, which produces H2O2 using electricity, offers a sustainable alternative, particularly suited for small-scale, continuous on-site H2O2 generation due to the portability of electrocatalytic devices. For efficient H2O2 electrosynthesis, electrocatalysts must exhibit high selectivity, activity, and stability for the two-electron pathway-oxygen reduction reaction (2e− ORR). Transition-metal chalcogenide (TMC)-based materials have emerged as promising candidates for effective 2e− ORR due to their high activity in acidic environments and the abundance of their constituent elements. This review examines the potential of TMC-based catalysts in H2O2 electrosynthesis, categorizing them into noble-metal and non-noble-metal chalcogenides. It underscores the importance of achieving high selectivity, activity, and stability in 2e− ORR. By reviewing recent advancements and identifying key challenges, this review provides valuable insights into the development of TMC-based electrocatalysts for sustainable H2O2 production.

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36

Wu, Fei, Yueying Wang, Shunxin Fei e Gang Zhu. "Co-Promoted CoNi Bimetallic Nanocatalyst for the Highly Efficient Catalytic Hydrogenation of Olefins". Nanomaterials 13, n. 13 (26 giugno 2023): 1939. http://dx.doi.org/10.3390/nano13131939.

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Bimetallic catalysts, especially non-noble metals, hold great potential for substituting for noble metals in catalytic hydrogenation. In present study, a series of CoxNiy (x + y = 6) bimetallic catalysts were prepared through the impregnation–reduction method and cyclohexene was chosen as probe-molecule to study the promotion effect of Co on the catalytic olefin hydrogenation reactions. Meanwhile, density functional theory (DFT) was utilized to investigate the formation energies and the charge distribution of CoNi bimetals, as well as the transition state (TS) searches for hydrogen dissociation and migration. The results suggest that bimetals tend to have superior catalytic performance than pure metals, and Co3Ni3 shows the highest catalytic activity on the cyclohexene hydrogenation. It was found that the charge transfer from Co to Ni and the alloying give rise to the refinement of CoNi grains and the improvement of its catalytic activity and stability. Thus, it may be possible to obtain better catalytic performance by tuning the metal/metal atomic ratio of bimetals.

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37

Tao, Chong, Limo He, Xuechen Zhou, Hanjian Li, Qiangqiang Ren, Hengda Han, Song Hu, Sheng Su, Yi Wang e Jun Xiang. "Review of Emission Characteristics and Purification Methods of Volatile Organic Compounds (VOCs) in Cooking Oil Fume". Processes 11, n. 3 (27 febbraio 2023): 705. http://dx.doi.org/10.3390/pr11030705.

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Volatile organic compounds (VOCs) in cooking oil fumes need to be efficiently removed due to the significant damage they cause to the environment and human health. This review discusses the emission characteristics, which are influenced by different cooking temperatures, cooking oils, and cuisines. Then, various cooking oil fume purification methods are mainly classified into physical capture, chemical decomposition, and combination methods. VOCs removal rate, system operability, secondary pollution, application area, and cost are compared. The catalytic combustion method was found to have the advantages of high VOC removal efficiency, environmental protection, and low cost. Therefore, the last part of this review focuses on the research progress of the catalytic combustion method and summarizes its mechanisms and catalysts. The Marse-van Krevelen (MVK), Langmuir-Hinshelwood (L-H), and Eley-Rideal (E-R) mechanisms are analyzed. Noble metal and non-noble metal catalysts are commonly used. The former showed excellent activity at low temperatures due to its strong adsorption and electron transfer abilities, but the high price limits its application. The transition metals primarily comprise the latter, including single metal and composite metal catalysts. Compared to single metal catalysts, the interaction between metals in composite metal catalysts can further enhance the catalytic performance.

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38

Yoon, Seo Jeong, Se Jung Lee, Min Hui Kim, Hui Ae Park, Hyo Seon Kang, Seo-Yoon Bae e In-Yup Jeon. "Recent Tendency on Transition-Metal Phosphide Electrocatalysts for the Hydrogen Evolution Reaction in Alkaline Media". Nanomaterials 13, n. 18 (21 settembre 2023): 2613. http://dx.doi.org/10.3390/nano13182613.

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Hydrogen energy is regarded as an auspicious future substitute to replace fossil fuels, due to its environmentally friendly characteristics and high energy density. In the pursuit of clean hydrogen production, there has been a significant focus on the advancement of effective electrocatalysts for the process of water splitting. Although noble metals like Pt, Ru, Pd and Ir are superb electrocatalysts for the hydrogen evolution reaction (HER), they have limitations for large-scale applications, mainly high cost and low abundance. As a result, non-precious transition metals have emerged as promising candidates to replace their more expensive counterparts in various applications. This review focuses on recently developed transition metal phosphides (TMPs) electrocatalysts for the HER in alkaline media due to the cooperative effect between the phosphorus and transition metals. Finally, we discuss the challenges of TMPs for HER.

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Guo, Yajie, Yongjie Liu, Yanrong Liu, Chunrui Zhang, Kelun Jia, Jibo Su e Ke Wang. "The High Electrocatalytic Performance of NiFeSe/CFP for Hydrogen Evolution Reaction Derived from a Prussian Blue Analogue". Catalysts 12, n. 7 (4 luglio 2022): 739. http://dx.doi.org/10.3390/catal12070739.

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Non-noble-metal-based chalcogenides are promising candidates for hydrogen evolution reaction (HER) by harnessing the architectural design and the synergistic effect between the elements. Herein, a porous bimetallic selenide (NiFeSe) nanocube deposited on carbon fiber paper (NiFeSe/CFP) was synthesized through a facile selenization reaction based on Prussian blue analogues (PBAs) as precursors. The NiFeSe/CFP exhibited excellent HER activity with an overpotential of just 186 mV for a current density of 10 mA cm−2 in 1.0 M KOH at ambient temperature, similar to most of the state-of-the-art transition metal chalcogenides. The corresponding Tafel slope was calculated to be 52 mV dec−1, indicating fast discharge of the proton during the HER. Furthermore, the catalyst could endure long-term catalytic tests and showed remarkable durability. The enhanced electrocatalytic performance of NiFeSe/CFP is attributed to the unique 3D porous configuration inherited from the PBA templates, enhanced charge transfer occurring at the heterogeneous interface due to the synergistic effect between the bimetallic phases, and the high conductivity improved by the formation of amorphous carbon shells during the selenization. These findings prove that the combination of inexpensive metal–organic framework precursors and hybrid metallic compounds is a feasible way to realize the performance enhancement of non-noble-metal-based chalcogenides towards alkaline HER.

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Li, Jiangtian, Deryn Chu, Connor Poland, Cooper Smith, Enoch A. Nagelli e Victor Jaffett. "XPS Depth Profiling of Surface Restructuring Responsible for Hydrogen Evolution Reaction Activity of Nickel Sulfides in Alkaline Electrolyte". Materials 18, n. 3 (25 gennaio 2025): 549. https://doi.org/10.3390/ma18030549.

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Abstract (sommario):

Electrochemical water splitting provides a sustainable method for hydrogen production. However, the primary challenge for electrochemical hydrogen generation is the high cost and limited availability of platinum-based noble-metal catalysts. Transition-metal chalcogenides have been identified as low-cost and efficient electrocatalysts to promote the hydrogen evolution reaction (HER) in alkaline electrolytes. Nonetheless, the identification of active sites and the underlying catalytic mechanism remain elusive. In this study, phosphorus-doped nickel sulfide has been successfully synthesized, demonstrating enhanced activity for alkaline HER. Investigating surface chemistry through X-ray photoelectron spectroscopy (XPS), depth profiling revealed that surface restructuring occurs during the HER process. The presence of phosphorus significantly influences this transformation, promoting the formation of a novel active Ni-O layer. This Ni-O layer is responsible for enhanced catalytic activity by upshifting the d-band center and increasing the density of states near the Fermi level, along with expanding the electrochemical surface area. This study reveals that the surface restructuring of transition-metal sulfides is highly tied to the electronic structure of the parent catalysts. Gaining a comprehensive understanding of this surface restructuring is essential for predicting and exploring more efficient non-precious transition-metal sulfide electrocatalysts.

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Yang, Kaixuan, Naimeng Chen, Xiaomiao Guo, Ruoqi Zhang, Xiaoyu Sheng, Hui Ge, Zhiguo Zhu, Hengquan Yang e Hongying Lü. "Phase-Controlled Cobalt Catalyst Boosting Hydrogenation of 5-Hydroxymethylfurfural to 2,5-Dimethylfuran". Molecules 28, n. 13 (22 giugno 2023): 4918. http://dx.doi.org/10.3390/molecules28134918.

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The search for non-noble metal catalysts for chemical transformations is of paramount importance. In this study, an efficient non-noble metal catalyst for hydrogenation, hexagonal close-packed cobalt (HCP-Co), was synthesized through a simple one-step reduction of β-Co(OH)2 nanosheets via a temperature-induced phase transition. The obtained HCP-Co exhibited several-times-higher catalytic efficiency than its face-centered cubic cobalt (FCC-Co) counterpart in the hydrogenation of the C=C/C=O group, especially for the 5-hydroxymethylfurfural (HMF) hydrogenation (8.5-fold enhancement). Density functional theory calculations demonstrated that HMF molecules were adsorbed more firmly on the (112_0) facet of HCP-Co than that on the (111) facet of FCC-Co, favoring the activation of the C=O group in the HMF molecule. The stronger adsorption on the (112_0) facet of HCP-Co also led to lower activation energy than that on the (111) facet of FCC-Co, thereby resulting in high activity and selectivity. Moreover, HCP-Co exhibited outstanding catalytic stability during the hydrogenation of HMF. These results highlight the possibility of fabricating hydrogenation catalysts with satisfactory catalytic properties by precisely tuning their active crystal phase.

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42

Wu, Ling-Wei, Yan-Fang Yao, Shi-Yin Xu, Xu-You Cao, Yan-Wei Ren, Li-Ping Si e Hai-Yang Liu. "Electrocatalytic Hydrogen Evolution of Transition Metal (Fe, Co and Cu)–Corrole Complexes Bearing an Imidazole Group". Catalysts 14, n. 1 (19 dicembre 2023): 5. http://dx.doi.org/10.3390/catal14010005.

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The study of the hydrogen evolution reaction (HER) by non-noble transition metals is of great significance for the production of hydrogen energy. In this work, a new 5,15-bis-(pentafluorophenyl)-10-[4-(1H-imidazole) phenyl]-corrole and its metal complexes (metal = Co, Cu, Fe) were synthesized and used for electrocatalyzed HER in DMF organic solvent and aqueous media. The prepared cobalt corrole showed the best catalytic performance in both media. Its turnover frequency (TOF) and catalytic efficiency (C.E) could reach 265 s−1 and 1.04 when TsOH was used as the proton source in a DMF solvent. In aqueous media, its TOF could also reach 405 h−1. The catalytic HER may go through an EECEC or ECEC (E: electron transfer, C: chemical step) pathway for these catalysts, depending on the acidity and concentration of the proton source. The present work successfully demonstrates that imidazole at a meso-phenyl group may improve the electrocatalytic HER activity of transition metal corroles.

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Ning, Cai, Yadong Zhang, Zhaoshun Meng, Chuanyun Xiao e Ruifeng Lu. "Computational Screening of Single Non-Noble Transition-Metal Atoms Confined Inside Boron Nitride Nanotubes for CO Oxidation". Journal of Physical Chemistry C 124, n. 3 (26 dicembre 2019): 2030–38. http://dx.doi.org/10.1021/acs.jpcc.9b10585.

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Kumaran, Yamini, Haralabos Efstathiadis e Iulian Gherasoiu. "Engineering Transition Metals As Noble-Metal Free Bifunctional Electrode for Overall Water Splitting". ECS Meeting Abstracts MA2022-02, n. 60 (9 ottobre 2022): 2523. http://dx.doi.org/10.1149/ma2022-02602523mtgabs.

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Abstract (sommario):

The emerging need of clean and renewable energy drives the exploration of effective strategies to produce molecular hydrogen. With the assistance of highly active non-noble metal electrocatalysts, electrolysis of water is becoming a promising candidate to generate pure hydrogen with low cost and high efficiency.[1] This reaction takes place almost exclusively on Pt/C catalysts at the cathode which is expensive and need to be replaced by a metal-based catalyst which can show a comparable HER (Hydrogen evolution reaction) activity. Transition metal oxides, nitrides and sulfides have been widely explored as catalysts for HER and OER (Oxygen evolution reaction) due to their good electronic conductivity, stable and variable oxidation states, and superior corrosion resistance.[2] In this research, MoNi4 embedded MoO3 nanorods are synthesized using facile hydrothermal method. Further, Molybdenum Vanadium Nitride is coated on top the synthesized electrode using RF/DC magnetron co-sputtering.[3] This combination of hydrothermal and magnetron sputtering fabrication methods of the electrodes results in high surface area of the electrodes thereby improving the reaction kinetics of hydrogen production. The performance of the electrodes is tested in N2/O2 saturated 1M KOH solution using steady state technique called Staircase Voltammetry (SCV) instead of conventional dynamic LSV (Linear sweep voltammetry)/CV (Cyclic Voltammetry).[4] This alternative method for testing is performed due to the exaggeration of the catalytic performance through conventional LSV/CV arising from double layer charging for nanostructured electrode. The electrodes are characterized by X-ray diffraction and SEM for structural and morphological analysis. Hence, we report the synthesis of novel MoVN on MoNi4/MoO2 nanorods using DC/RF Magnetron co-sputtering as an efficient, bifunctional, binder free electrode for overall water splitting. The electrode is characterised for both full-cell and half-cell configurations proving its stability for 12 hours. This work provides a reliable approach to the production of low cost and high-effectiveness electrodes for the application in commercial electrolyzers. [1] J. Zhang et al., “Efficient hydrogen production on MoNi4 electrocatalysts with fast water dissociation kinetics,” Nat. Commun., vol. 8, no. May, pp. 1–8, 2017, doi: 10.1038/ncomms15437. [2] L. A. Santillán-Vallejo et al., “Supported (NiMo,CoMo)-carbide, -nitride phases: Effect of atomic ratios and phosphorus concentration on the HDS of thiophene and dibenzothiophene,” Catal. Today, vol. 109, no. 1–4, pp. 33–41, 2005, doi: 10.1016/j.cattod.2005.08.022. [3] B. Wei et al., “Bimetallic vanadium-molybdenum nitrides using magnetron co-sputtering as alkaline hydrogen evolution catalyst,” Electrochemistry Communications, vol. 93. pp. 166–170, 2018, doi: 10.1016/j.elecom.2018.07.012. [4] S. Anantharaj and S. Kundu, “Do the Evaluation Parameters Reflect Intrinsic Activity of Electrocatalysts in Electrochemical Water Splitting?,” ACS Energy Lett., vol. 4, no. 6, pp. 1260–1264, 2019, doi: 10.1021/acsenergylett.9b00686. Figure 1

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Zhiquan Hou, Wenbo Pei, Xing Zhang, Yuxi Liu, Jiguang Deng e Hongxing Dai. "Oxidative Removal of Volatile Organic Compounds over the Supported Bimetallic Catalysts". Global Environmental Engineers 7 (16 luglio 2020): 1–27. http://dx.doi.org/10.15377/2410-3624.2020.07.1.

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Abstract (sommario):

Volatile organic compounds (VOCs) and methane are pollutants that are harmful to the atmosphere and human health. It is highly required to control emissions of VOCs. Catalytic oxidation is one of the most effective pathways for the elimination of VOCs, in which the key issue is the development of novel and high-performance catalysts. In this review article, we briefly summarize the preparation strategies, physicochemical properties, catalytic activities, and stability for the oxidative removal of VOCs of the supported bimetallic catalysts that have been investigated by our group and other researchers. The supported bimetallic catalysts include the supported noble bimetal, supported noble metal-transition metal, and supported non-precious bimetal catalysts. It was found that catalytic performance was related to one or several factors, such as specific surface area, pore structure, particle size and dispersion, adsorbed oxygen species concentration, reducibility, lattice oxygen mobility, acidity, reactant activation ability, and/or interaction between bimetals or between metal and support. The stability and ability of anti-poisoning to water, carbon dioxide or chlorine were related to the nature of the bimetal and support in the catalysts. In addition, we also envision the development trend of such a topic in the future work.

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Avinash, Kiran, K. R. Rohit e Gopinathan Anilkumar. "Iron, Cobalt and Nickel-catalyzed Hydrosilylative Reduction of Functional Groups". Current Catalysis 10, n. 3 (dicembre 2021): 179–205. http://dx.doi.org/10.2174/2211544710666211108095557.

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Abstract: Hydrosilylation is an important transformation in organic synthesis. It has displayed widespread applications in homogenous catalysis and in the commercial production of organosilanes and organosilicon compounds. Though metals like Ru, Rh etc., were used widely for achieving hydrosilylation, the increasing environmental concerns and the search for less expensive alternatives resulted in the investigation of transition metals. Metals like Ni, Co etc., exhibit potential cost benefits, in addition to their low CO2 footprint and lower toxicity. Thus, transition metal catalysis has emerged as a promising strategy for hydrosilylation. This comprehensive review discusses the catalytic hydrosilylation of various functional groups with non-noble transition metals such as iron, cobalt and nickel in the last decade. Here, the topic is categorized based on the substrate functional groups such as aldehydes, ketones, alkenes, etc.

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Li, Jiangtian, Deryn Chu, David R. Baker e Rongzhong Jiang. "(Invited) Regulating Electronic Structure for Clean Energy Powered Water Electrolysis on Non-Precious Catalysts". ECS Meeting Abstracts MA2022-01, n. 38 (7 luglio 2022): 1690. http://dx.doi.org/10.1149/ma2022-01381690mtgabs.

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Abstract (sommario):

The need for clean energy, predominantly wind and sun, to replace fossil fuels is in high demand for the carbon neutrality. The intermittent nature of the renewable energy sources is one of the most important challenges. A potential solution is to store the extra electricity in the form of chemical fuels, and then reconvert on demand. Electrochemical water splitting to produce hydrogen and oxygen is an appealing and sustainable approach. The benchmark electrocatalysts for water electrolysis are noble metal Pt- and Ir/Ru-based materials. Nevertheless, the scarcity and the high cost of these precious catalysts severely hinder their widespread applications. Developing non-precious electrocatalysts has been one long-term target, but still remains a great challenge. In this presentation we will show our research efforts and design strategies by regulating the electronic structures on transition metal-based electrocatalysts for hydrogen evolution, oxygen evolution as well as constructing the water electrolyzer powered by solar energy.

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Zhou, Zhaoyu, Yongsheng Jia, Qiang Wang, Zhongyu Jiang, Junwu Xiao e Limin Guo. "Recent Progress on Molybdenum Carbide-Based Catalysts for Hydrogen Evolution: A Review". Sustainability 15, n. 19 (7 ottobre 2023): 14556. http://dx.doi.org/10.3390/su151914556.

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Abstract (sommario):

Hydrogen is an ideal alternative energy for fossil fuels to solve aggravating environmental and energy problems. Electrocatalytic hydrogen evolution reaction (HER) driven by renewable electricity (sunlight, wind, tide, etc.) is considered to be one of the most promising approaches for hydrogen production. However, its large-scale applications are greatly limited by the use of noble platinum (Pt) group electrocatalysts. As an earth-abundant/non-noble HER catalyst, molybdenum carbide (MoxC: MoC or Mo2C) has attracted extensive attention in the field of sustainable hydrogen production due to its excellent Pt-like catalytic activity, low cost, high chemical stability, and natural abundance. In this review, the progress on the strategies for optimizing the catalytic activity of MoxC is summarized, including optimization of synthesis methods, composites with carbon material, non-precious metal doping, transition metal doping, construction of the heterogeneous structure, etc. Among them, the importance of sulphur-doping, Ni-doping, and heterophase structure on molybdenum carbide-based catalysts for enhancement of HER activity has been highlighted. In addition, molybdenum carbide-based bi-functional catalysts are presented for the application in full water splitting. Finally, several effective strategies for molybdenum carbide-based catalyst design are concluded, and challenges remained in electrocatalytic water splitting are raised. Future development trends and perspectives for this promising material are also discussed.

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Carroll, Zachary Liam, Michel Haché, Bowen Wang, Lixin Chen, Uwe Erb, Steven Thorpe e Yu Zou. "Electrodeposition of Non-Noble High-Entropy Alloys for Effective Hydrogen Evolution Electrocatalysts". ECS Meeting Abstracts MA2024-01, n. 34 (9 agosto 2024): 1874. http://dx.doi.org/10.1149/ma2024-01341874mtgabs.

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As society works towards reducing its carbon footprint, various sectors such as energy, steelmaking and fertilizer production have begun to look increasingly towards decarbonization. Hydrogen production through electrolysis, when linked to renewables (solar, wind), provides a promising low-emission alternative as an energy carrier and chemical feedstock. With the decreasing cost of said renewables, greater focus is now on the capital cost of the electrolyser, and particularly the membrane/electrode structures. Conventional Proton Exchange Membrane (PEM) electrolysers rely on the use of electrocatalysts made with expensive noble metals such as platinum, ruthenium, and palladium [1]. Anion Exchange Membrane (AEM) electrolysers present an effective means of alkaline water splitting with low carbon emissions and can effectively utilize non-noble metal electrocatalysts for the Hydrogen Evolution Reaction (HER). A novel class of materials, High-Entropy Alloys (HEAs), made of non-noble metals or with reduced noble metal content have shown great promise as active electrocatalytic materials [2]. HEAs are typically defined as metal alloys made of five or more constituent elements each comprising at least 5% of the total material [3]. Having such a large number of principal alloying elements can lead to enhanced phase stability due to an increased configurational entropy, have unique chemical clustering, and can help prevent degradation of the material in harsh environments [2]. Additionally, the large lattice parameter mismatch between constituent elements can result in a high degree of strain which can help shift electronic states in a way that is favourable to hydrogen electrocatalysis [4]. These properties along with the so called “cocktail effect,” whereby combining multiple elements can result in unexpected synergistic interactions, makes HEAs uniquely suited to electrocatalytic applications [5]. In this work, we investigate the electrocatalytic performance of electrodeposited FeNiCoMoW HEAs. The goal is to combine three hyper-d transition metals with two hypo-d transition metals to alter the electronic structure and improve electrocatalytic performance. Using chronoamperometric measurements, the Tafel slopes for FeNiCoMoW HEAs electrodeposited at pH 5, 6 and 7 were determined, with the pH 5 HEA demonstrating the smallest average Tafel slope of approximately 83 mV/dec. Compared to some electrodeposited binary alloys reported on in the literature, this marks an improvement and may be the result of unexpected interactions within the compositionally complex alloy. In the FeNiCoMoW HEA, the magnitude of the Tafel slope increased in tandem with the electrochemically active surface area (ECSA) as determined by Cyclic Voltammetry (CV) which suggests that the composition may be more important for improving performance. As the pH of the electrodeposition solution increased, the amount of cobalt in the as-deposited HEA decreased while the amounts of molybdenum and tungsten remained constant. The composition of nickel and iron appeared to vary inversely, reaching a maximum and minimum respectively at pH 6. From these results it seems that maximizing cobalt content and minimizing nickel content could potentially help to improve HER performance in the FeNiCoMoW system. References: [1] J. Song et al., “Implementation of Proton Exchange Membrane Water Electrolyzer with Ultralow Pt Loading Cathode through Pt Particle Size Control,” ACS Sustain. Chem. Eng., vol. 11, no. 45, pp. 16258–16266, Nov. 2023, doi: 10.1021/acssuschemeng.3c04679. [2] G. M. Tomboc, T. Kwon, J. Joo, and K. Lee, “High entropy alloy electrocatalysts: a critical assessment of fabrication and performance,” J. Mater. Chem. A, vol. 8, no. 30, pp. 14844–14862, Aug. 2020, doi: 10.1039/D0TA05176D. [3] J.-W. Yeh et al., “Nanostructured High-Entropy Alloys with Multiple Principal Elements: Novel Alloy Design Concepts and Outcomes,” Adv. Eng. Mater., vol. 6, no. 5, pp. 299–303, 2004, doi: 10.1002/adem.200300567. [4] T. Löffler et al., “Toward a Paradigm Shift in Electrocatalysis Using Complex Solid Solution Nanoparticles,” ACS Energy Lett., vol. 4, no. 5, pp. 1206–1214, May 2019, doi: 10.1021/acsenergylett.9b00531. [5] Y. Zhang, D. Wang, and S. Wang, “High-Entropy Alloys for Electrocatalysis: Design, Characterization, and Applications,” Small, vol. 18, no. 7, p. 2104339, 2022, doi: 10.1002/smll.202104339. Figure 1

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Tran, Phong D., Lifei Xi, Sudip K. Batabyal, Lydia H. Wong, James Barber e Joachim Say Chye Loo. "Enhancing the photocatalytic efficiency of TiO2 nanopowders for H2 production by using non-noble transition metal co-catalysts". Physical Chemistry Chemical Physics 14, n. 33 (2012): 11596. http://dx.doi.org/10.1039/c2cp41450c.

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