Дисертації з теми "Bimetallic nano"
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Khimyak, Tetyana. "New bimetallic clusters - precursors for heterogeneous nano-catalysts." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620698.
Jegadeesan, Gautham. "Environmental catalysis using nano-sized bimetallic particles : selenium remediation /." Available to subscribers only, 2005. http://proquest.umi.com/pqdweb?did=1068236761&sid=29&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Snyder, Brian. "An investigation into bimetallic hollow nanoparticles in catalysis." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47614.
Agarwal, Shirish. "Palladium/Magnesium Bimetallic Systems for Dechlorination of Polychlorinated Biphenyls." Cincinnati, Ohio : University of Cincinnati, 2009. http://www.ohiolink.edu/etd/view.cgi?acc_num=ucin1236037376.
Advisors: Dionysios Dionysiou (Committee Chair), Souhail Al-Abed (Committee Member), George Sorial (Committee Member), Margaret Kupferle (Committee Member). Title from electronic thesis title page (viewed April 22, 2009). Keywords: PCBs; Dechlorination; Pd/Mg; Bimetallic; Reduction pathway; intermediates; aggressive anions; sediment; nano-synthesis; nano-scaling; sulfide poisoning. Includes abstract. Includes bibliographical references.
Liao, Fenglin. "The development of Pd-based bimetallic nano-catalysts in green chemistry." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:2fb03ce6-ba32-4102-96fc-f00fc7593bc0.
Kane, Kenneth. "Metallic systems at the nano and micro scale: Bimetallic nanoparticles as catalysts and MCrAlY bond coats in thermal barrier coatings." VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/5732.
Forel, Salomé. "Single wall carbon nanotube growth from bimetallic nanoparticles : a parametric study of the synthesis up to potential application in nano-electronics." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX094/document.
This manuscript presents an experimental study around the single wall carbon nanotubes (SWCNT) synthesis and their possible integration in nanodevices. The unique electronic and optical properties of carbon nanotubes make them a choice material for various applications, particularly in nano-electronics.Nevertheless, their integration in effective devices is still a challenge. This is mainly due to the difficulty to obtain large quantity of SWCNT with uniform properties, defined by their structure (i.e. chiral angle and diameter). Therefore, structure controlled growth of SWCNTs is a key point for progress in this field.Here, we established a new synthesis approach based on coordination chemistry and hot-filament chemical vapor deposition. This approach allows the design of various bimetallic catalyst nanoparticles for the SWCNT growth. As the synthesis process is generic, parametric study can be performed in order to better understand the influence of the various parameters on the structure of the as-grown SWCNTs. In particular, we will discuss the role of the growth temperature and the chemical composition of the catalyst on the final SWCNTs structure. The obtained SWCNTs are mainly characterized by Raman spectroscopy and electronic microscopy.In order to validate the observations performed by Raman measurement, the synthesized SWCNTs have been also integrated in field effect transistors (FET) devices. An analysis of the performance of the FET-device as a function of the SWCNTs used in its channel will be presented.Finally, SWCNTs integrated in these transistors have been functionalized with an inorganic chromophore of ruthenium.We demonstrate that the functionalization of the SWCNTs leads to a three order of magnitude reversible switch of the device conductivity triggered by visible light
McCoppin, Jared Ray. "FABRICATION AND MASS TRANSPORT ANALYSIS OF TAPE CAST NANO-SILVER HIGH TEMPERATURE SOLDER." Wright State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=wright1389285958.
Maknun, Luluil. "Development of mass spectrometric analytical methods for the determination of iron complexes in plants and bacteria and for the determination of cobalt using bimetallic nanoparticles." Electronic Thesis or Diss., Pau, 2023. http://www.theses.fr/2023PAUU3039.
The research focuses on an analytical method development using chromatography coupled to mass spectrometry for the analysis of low molecular weight iron complexes. In the second part, the study explores the utilization of bimetallic nanoparticles for Co2+ detection.In the first part, a method using liquid chromatography with two detector mass spectrometry, i.e., electrospray high-resolution accurate mass (HRAM) mass spectrometry (MS) and inductively coupled mass spectrometry (ICP-MS), was developed for the analysis of low molecular weight iron (Fe) complexes, called ‘siderophores'. The complexity of the samples, their low concentrations, and the lability of the iron complexe were challenges in the development of methods for their identification and quantification. For the sample clean-up, solid phase extraction (SPE) using acidic conditions was developed to purify the samples, followed by evaporation to dryness. The individual 56Fe-siderophore complexes were identified by fast size-exclusion chromatography (FastSEC) - Orbitrap MSn based on the exact molecular mass (+ 1 ppm) and MS2. Their capability of exchanging the natural 56Fe with the spiked 58Fe was demonstrated by SEC with ICP-MS and ESI-MS detection. The method was applied to the analysis of peat collected in the Eastern part of the French Pyrenean mountains. Nineteen siderophores belonging to four different classes were presumptively identified and quantified. The results were compared with ICP-MS detection of iron and matching of the sum of the moles of iron complexes determined by the isotopic- ESI-MS within each peak as eluted from the fastSEC column.In the second part, a method using inductively coupled plasma mass spectrometry in the single particle mode and the conventional mode coupled to a flow field flow fractionation was developed to select suitable conditions for the synthesis of Ag-Au bimetallic nanoparticles and to monitor the colorimetric changes due to aggregations. Ag-Au BNPs, synthesized by using citrate reduction of Ag and Au ions, were used as sensors for the detection of Co2+. To better understand the colorimetric sensing of Co2+ using the Ag-Au BNPs, various mixtures were studied, viz. (i) only Ag-Au BNPs; (ii) Ag-Au BNPs with thiosulfate; (iii) Ag-Au BNPs with thiosulfate and ethylenediamine; and (iv) Ag-Au BNPs with thiosulfate, Co2+ and ethylenediamine. SP-ICP-MS was used to determine the core size, size distribution, and number concentration, as well as the heterogeneity of the particles synthesized by using various citrate concentrations and metal ratios. Fl-FFF-ICP-MS was also used to observe the hydrodynamic size and the Ag: Au signal intensity ratio of the BNPs to support information obtained from the SP-ICP-MS. The combination of the proposed techniques has been applied to monitor the reaction during colorimetric sensing. Additional information from fractograms provided by Fl-FFF-ICP-MS was also useful for the understanding of the aggregation of BNPs arising from the [Co(II)(en)3]2+ complex surrounding the surface of the BNPs. Furthermore, when compared to colorimetric sensing, the limit of detection for Co2+ ion, using the BNPs and SP-ICP-MS, were 20-fold lower, decreasing from ppb to ppt levels
Béjaud, Romuald. "Formation et extension de macles de déformation dans des nanostructures cfc : simulations numériques." Thesis, Poitiers, 2017. http://www.theses.fr/2017POIT2318.
For several decades, the elaboration of nano-structured materials tends to develop more and more. Indeed, these materials often show interesting properties, and in particular surprising mechanical properties when compared to their bulk counterparts. For example, nano-twinned or nano-layered metals are known to have ultra-high mechanical strength, good thermal stability, and very good radiation resistance. As the interface spacing decreases to the nanometer-scale, the density of interfaces increases significantly and subsequently the macroscopic properties become largely governed by the interface-defect interactions. In that context, we have studied deformation twin formation and mechanisms of interaction between a new formed twin and a preexisting interface (a twin boundary or a bimetallic interface), using atomistic simulations and a thin film model configuration. First results show the influence of surface steps on mechanical twinning, for a model system without interface. Then we identify a new mechanism leading to the formation of a Lomer dislocation, following the interaction of a newly formed twin and a preexisting twin boundary. By varying the density of surface defects, we show the particular influence of a preexisting twin boundary on twin size and number. Finally, for the Cu/Ag bimetallic system, our results highlight the role of epitaxial dislocations (at the interface) in twin nucleation and extension as well as a direct influence of the interface type in twin propagation
You, Sheng Mu. "Metal organic frameworks as efficient photosensitizer for TiO₂ nanoarray anode and application to water splitting in PEC cells Fe/Ni Bimetallic organic framework deposited on TiO₂ nanotube array for enhancing higher and stable activity of oxygen evolution reaction Novel nano-architectured water splitting photoanodes based on TiO₂-nanorod mats surface sensitized by ZIF-67 coatings Surface sensitization of TiO₂ nanorod mats by electrodeposition of ZIF-67 for water photo-oxidation Electrochemically capacitive deionization of copper (II) using 3D hierarchically reduced graphene oxide architectures." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASF015.
The fossil fuel reserves are dwindling and their unrestricted use has generated profound changes in Earth's surface temperature and climate. Storing solar energy in the form of hydrogen produced by dissociation of water is an ideal way to mitigate global warming. Materials from the “metal organic framework” (MOF) family are starting to be used as photo-electrocatalysts, especially for photo-dissociation of water. Their extremely high porosity and their great versatility, both chemical and structural, designate them as potential candidates to facilitate the absorption of solar radiation and catalyze the dissociation of water in photoelectrochemical cells. By controlling the chemical composition and doping of the linker used in the MOF, it is possible to adjust the band gap energy, to favor the functionalization on very varied substrates or even to adjust their resistance to corrosion in various chemical environments. They are therefore materials of great interest for catalysis, electrocatalysis or photo-electro-catalysis. On the other hand, nano-structured TiO₂, for example in the form of nanotube or nanowire mats, sometimes called TiO₂ nanoarray (TNA), is a material very suitable for the construction of photoanodes for the evolution of oxygen in aqueous medium. It has already been extensively studied and described in the literature. During our thesis, we manufactured composite materials made up of MOFs of transition metals (Ni, Co, Fe) deposited on TNA (network of nanotubes or nanowires). For this we used an electrochemical method of electrodeposition (cyclic voltammetry). This allowed us to deposit metallic nanoparticles on TNA with fixed potential - 1.0 V and then transform them by chemical reaction with organic ligands (1,3,5-benzenetricarboxylic acid, BTC, 1,4-benzenedicarboxylic acid, BDC and imidazole, 2MZ) by thermal-thermal route. The materials obtained exhibit significant electrocatalytic activity and excellent photoelectrochemical durability. These composite materials have been successfully used as an active phase in photo-electrodes for the oxygen release reaction (OER)
Yuan, Xiaojiao. "Nanostructures based on conjugated polymer polypyrrole for application in photocatalysis Photocatalytic degradation of organic pollutant with polypyrrole nanostructures under UV and visible light Polypyrrole nanostructures modified with mono- and bimetallic nanoparticles for photocatalytic H2 generation Highly active composite TiO2-polypyrrole nanostructures for water and air depollution under visible light irradiation Highly Promoted Photocatalytic Hydrogen Generation by Multiple Electron Transfer Pathways Visible light-driven simultaneous water oxidationand quinone reduction by a nano-structuredconjugated polymer without co-catalysts." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASF011.
Recently, π-conjugated polymer nanostructures (CPNs) emerge as a new class of catalysts for various photocatalytic applications such as water splitting, CO2 reduction, water treatment (degradation of organic pollutants and heavy metals reduction). Among the family of CPs, polypyrrole PPy has been the most extensively investigated owing to its environmental stability, facile synthesis, excellent stability. In this thesis, PPy nanostructures were synthesized by different methods: chemical polymerization by soft templates (hexagonal or lamellar mesophases) and polymerization by radiolysis. These PPy nanostructures exhibit promising photocatalytic activity for organic pollutants (phenol and methyl organge) degradation under visible light and their activities are higher than that of PPy- bulk.Besides, we modified TiO2 with nanostructured PPy for photodegradation of organic pollutants (methy orange and phenol as model water pollutants and toluene as air pollutant). The nanocomposite shows an important increase of the photocatalytic performance under UV and visible light compared to bare TiO2 and PPy. This work offers a facile and cheap way to fabricate the heterojunction in organic-inorganic hybrid materials interface and the composite nanomaterials represents a promising photocatalyst for water treatment and indoor application. In another hand, green hydrogen production by photocatalytic water splitting offers a promising way to solve environment and energy issues. In this thesis, we have shown that modified conjugated polymer polypyrrole nanostructures with mono- and bimetallic (Pt, Ni, Pt-Ni) nanoparticles are very active for hydrogen generation, and that a synergistic effect is obtained by alloying Pt with Ni. Lastly, different ternary nanostructures based on PPy-TiO2 composites with controlled active sites modification with Pt nanoparticles were developed ((Pt-PPy)-TiO2, (Pt-TiO2)-PPy and Pt-(PPy-TiO2)). The photocatalytic activity of Pt-(PPy-TiO2) for hydrogen generation under UV and visible light is very high and drastically surpasses those of (Pt-PPy)-TiO2 and (Pt-TiO2)-PPy
Chienyu, Lin, and 林建宇. "Degradation of Perchloroethylene with Dispersed Nano-Fe and Nano-Pd/Fe Bimetallic Particles." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/74164173080296401990.
國立屏東科技大學
環境工程與科學系所
99
Chlorinated organic compounds are widely used in chemical, agricultural, and pharmaceutical industries. However, if the storage, use, and disposal of those compounds are not properly handled, they may leak into soil, and further pollute the aquifer. Chlorinated solvents due to their high acute toxicity and bioaccumulation cause environmental pollution and are harmful to human body. In this study, some modification techniques of nano zero valent iron (NZVI) were utilized to enhance the degradation of perchloroethylene (PCE). The experimental design included four stages. The first one was to select NZVI as the reactive materials for degradation of PCE. The second one was to coat palldium (Pd) onto NZVI as surface active agents to synthesize the nano-Pd/Fe bimetallic particles (nano-Pd/Fe). The third one was to employ the dispersed technology to raise the dispersion of NZVI using carboxymethyl cellulose (CMC) as dispersant. And the last one was to add CMC in solution to enhance the dispersion of nano-Pd/Fe. The average size, measured by particle size analyzer, of lab-synthesized NZVI, dispersed NZVI, nano-Pd/Fe (weight ratios of Pd to Fe of 1:100, 1:250, 1:500) and dispersed nano-Pd/Fe were between 101.5 to 111.1 nm. NZVI had the lowest specific surface area of 38.04 m2 g-1 and nano-Pd/Fe 1:100 had the largest one of 56.05 m2 g-1. The specific surface area of nano-Pd/Fe increased with higher Pd contents. In the PCE blank tests, PCE concentration did not obviously varied under various test conditions. Addition of CMC and buffer solution had little effects on PCE concentration and therefore would not interfere with the subsequent batch tests. For the tests of PCE degradation with NZVI and various proportions of nano-Pd/Fe, NZVI did not fully degrade PCE while various proportions of nano-Pd/Fe (1:100, 1:250, 1:500) did completely degrade PCE. It showed that the reduction capacity of nano-Pd/Fe on PCE degradation was obviously higher than that of NZVI. The pseudo first order reaction rate constant (kobs) of NZVI and nano-Pd/Fe (1:100, 1:250, 1:500) were 0.14, 2.55, 1.51, 1.59 hr-1, respectively. The more the amount of Pd contents on Pd/Fe particles, the higher their degradation capacity on PCE. For the tests of dispersed NZVI and nano-Pd/Fe on PCE degradation, both of 2.5 g and 5 g dispersed NZVI and 5 g dispersed nano-Pd/Fe was able to entirely degrade PCE. The kobs of various amounts of dispersed NZVI (5 g, 2.5 g, 1 g) and dispersed nano-Pd/Fe (5 g) were 2.88, 1.68, 0.62, and 10.45 hr-1, respectively. It showed that nano particles with dispersant could enhance their degradation capacity on PCE. For the tests of various pH buffer on PCE degradation, PCE was completely degraded with 5 g of Pd/Fe at reaction time of 3 min of the first sampling at pH buffer of 4, 7, and 8. At pH buffer equal to 9, PCE degradation with NZVI and nano-Pd/Fe was minimal. PCE As the amount of nano-Pd/Fe reduced to 1 g, PCE was also fully degraded at reaction time of 80 min at pH buffer of 8 with kobs equal to 3.08 hr-1 which was higher than that (2.55 hr-1) of 5 g nano-Pd/Fe without pH buffer. The kobs value of 0.31 hr-1 for 5 g NZVI at pH buffer of 8 was also higher than that (0.14 hr-1) without pH buffer. The concentration of Cl- released from PCE degradation was close to the theoretical release amount of Cl-. The higher the PCE degradation, the greater the Cl- concentration releases. In this study, dechlorinated by-products were not detected. The contents on the surface of nano particles measured by SEM-EDS showed no obvious differences under various test conditions. The surface morphology of nano particles observed by SEM also showed chain-like distribution and no significant variations between pre-reacted and post-reacted with PCE. With FTIR identification, some differences at wave number of 620 and 1110 cm-1 were observed on the surface of nano particles pre- and post-reacted with PCE. To solve the aggregation phenomenon of NZVI with dispersant will greatly enhance its reduction capacity on pollutants. NZVI modification with Pd plating and CMC dispersant to form dispersed nano-Pd/Fe is feasible and can significantly enhance the degradation of PCE that can provide an alternative for in-situ remediation of chlorinated solvents. Keywords: perchloroethylene (PCE), nano zero valent iron (NZVI), palladium/iron bimetal, carboxymethyl cellulose
Yeh, Charng-Ching, and 葉長青. "Supported Pt-Based Bimetallic Anodic Nano-Catalysts For Direct Methanol Fuel Cells." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/71357412433995910455.
義守大學
生物技術與化學工程研究所碩士班
94
This research is aimed at studying the preparations of anodic nano-catalysts for direct methanol fuel cells by a method of modified polyol reduction, utilizing ethylene glycol (EG), diethylene glycol (DiEG) and triethylene glycol (TriEG) as reducing agent and solvent. Metals such as Sn, W, Mo and Ru, as well as carbon black and multi-walled carbon nano-tubes were employed for the fabrication of supported Pt-based bimetallic catalysts to explore effects on the anodic behaviors of methanol electro-oxidation and CO tolerance. Electrochemical investigations involving cyclic voltammetry, chronoamperometry and chronopotentiometry coupled with analytical tools of x-ray diffraction (XRD), transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS) were undertaken to establish a novel technology to prepare nano-catalysts most appropriate for DMFC anodes. It was found that catalysts fabricated by TriEG as reducing agent and multi-walled carbon nanotube as support exhibited far better anodic behaviors than those prepared by DiEG and EG and carbon black, respectively. This is attributable to the smaller particle size and better dispersion obtained with TriEG and multi-walled carbon nanotube. Pt-Sn/MWCNT catalysts exhibited the most superior anodic behaviors among the carbon black- or MWCNT-supported alloys of Pt-Sn, Pt-W, Pt-Mo and Pt-Ru. The particle size of the alloys prepared ranged from 3 to 6 nm, proving that the preparation method developed is highly effective to fabricate nano-catalysts. In view of the fact that particle size and size distribution depend on the rate of particle nucleation, microwave irradiation of the precursor solutions was sought in order to enhance reducing reaction. As a result, the microwave-irradiated samples exhibited better anodic properties in terms of methanol electro-oxidation and drastically shorten processing time than those heated in conventional oven. Fabricated in this manner, the TriEG-prepared catalysts also exhibited better anodic behaviors. Thus, microwave irradiation may prove to be a promising method to fabricate anodic nano-catalysts for DMFC.
Thanh, Nguyen, and 阮台彥. "Remediation of Pentachlorophenol-contaminated Soil with Nano-zero Valent Iron and Bimetallic Iron." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/05517422225253718703.
國立中央大學
環境工程研究所
100
Zerovalent iron and bimetallic iron have been studied mostly for the degradation of chlorinated compounds in aqueous phase. In this study, laboratory synthesized particles of nano zerovalent iron and commercial bimetallic iron were applied to investigate the reduction kinetics and degradation mechanisms of pentachlorophenol (PCP) spiked sandy soil. Degradation of PCP by nZVI and BioCAT follows the first-order kinetics. The 98% PCP removal efficiency from soil slurries in contact with nano zerovalent iron (nZVI) was mostly attributable to adsorption to nZVI surfaces and only 4% was due to dechlorination. By comparison, approximately 70% dechlorination rate were achieved along with 90% PCP removal efficiency with BioCAT dosage of 600 mg after 21 days of treatment. Possible explainations for the differences in the reaction rates between iron and bimetallic iron may involve competitive sorption of chlorinated phenols and reactive hydrogen on iron and catalytic surfaces as well as the effects of sorption on corrosion. PCP dechlorination was confirmed by the appearance of the intermediate products as well as chloride release. Additionally, the increase of pH values and rapid decrease of ORP values during the reaction also proved reductive dechlorination of PCP. The lower chlorinated phenols and the endproduct including three TeCP isomers; four TrCP isomers; four DCP isomers; two MCP isomers and phenol by BioCAT were found. The intermediates by nZVI contained one TeCP isomer, one TCP isomer. The stepwise dechlorination pathways of PCP by nZVI and BioCAT were proposed in this study. After reductive dechlorination reactions, these intermediates are less toxic than PCP. Furthermore, these lower chlorinated phenols can be biodegraded or photodegraded more easily than PCP in the environment. These findings indicate that using BioCAT with mild temperature and no pH adjustment could have implications for field treatment of PCP-contaminated soil.
Lin, Ming-Hei, and 林明憙. "Electrolysis-Enhanced Permeable Reactive Barrier Packed with Nano-Pd/Fe Bimetallic Particles of Perchloroethylene." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/52050176023193793112.
國立屏東科技大學
環境工程與科學系所
100
The aim of this study is to investigate the degradation efficiency of target pollutant, perchloroethylene (PCE), by nano-palladium/iron (Pd/Fe) bimetallic metal particles enhanced by electrolysis. The experiments were divided into four stages. The first stage was to characterize the properties of quartz sand and nano-Pd/Fe particles. The second stage was to conduct the batch tests under various pH values (pH 8-9) on the effects of PCE degradation with nano-Pd/Fe. The third stage was to observe the transport behaviors of solutes through the porous media in a bench-scale sand box. And the fourth stage was to identify the variations of nano-Pd/Fe before and after the reaction with PCE by SEM-EDS and FTIR analysis. The average size and specific surface area of lab-synthesized nano-Pd/Fe particles were 111.1 nm and 56.05 m2 g-1, respectively. The absorption peaks of nano-Pd/Fe analyzed by the X-ray diffraction detector (XRD) only identified Fe. That may be due to the trace amount of Pd on bimetallic metals. For the tests of various pH values (pH 8-9) on PCE degradation with nano-Pd/Fe, the efficiency decreased with higher pH values. The concentration of Cl- released from PCE degradation was close to the theoretical values. The PCE degradation levels were positive correlated with the release amounts of Cl-. In this study, the by-products of PCE degradation such as trichlorethylene (TCE), cis-1,2-dichloroethylene (cis-1,2-DCE), trans-1,2-dichloroethylene (trans-1,2-DCE), 1,1-dichloroethylene (1,1-DCE), and vinyl chloride (VC) were not detected. Via the tracer tests, the average residence time was about 1.7 times higher than the theoretical value. For the test of permeable reactive barrier (PRB) packed with nano-Pd/Fe on PCE degradation, the duration of reactivity of nano-Pd/Fe could be maintained about 28 hr which was around 2 to 4 times higher than that of nano zero valent iron. During the tests, ORP values were steadily maintained below -300 mV in the PRB showing a reduction state was kept in the system. Dechlorination of PCE with nano-Pd/Fe particles were identified by the significant increase of Cl- concentration. The test of nano-Pd/Fe PRB enhanced by electrolysis on PCE degradation, H+ released near the anode was able to acid-washed the surface of Pd/Fe particles to increase their reactivity. The results showed that PCE was not completely degraded by the nano-Pd/Fe particles. The reactivity of Pd/Fe was observed to maintain about 16 to 20 hr. Therefore, more researches on the aspects of current, potential, and electrolyte to the performance of electrolysis enhanced PRB packed with nano-Pd/Fe technology are needs to facilitate its application to in-situ remediation of groundwater contaminated by chlorinated solvents. From the images observed by SEM-EDS, the surface morphology of nano-Pd/Fe particles displayed chain-like structure and irregular flakes pre-reacted and post-reacted with PCE, respectively. The spectrum of fresh nano-Pd/Fe particles analyzed by FTIR showed that a strong and broad absorption signal ranged from 3200 to 3500 cm-1 was identified to be O-H and at 1539, 1385, 967 cm-1 to be the nitro compounds (NO2), alkane (CH3), and alkene (C = CH), respectively. Finally, a signal ranged from 600 to 800 cm-1 was C-Cl. Keywords: perchloroethylene, nano-palladium/iron, tracer, permeable reactive barrier, electrolysis
Yeh, Min-Hsin, and 葉旻鑫. "Fabrication of Homogeneously-structured PtIr Bimetallic Nano-Catalyst/Glucose Oxidase Composite Electrode and its Applications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/75437610847365454270.
國立臺灣科技大學
化學工程系
97
This investigation mainly consists of two topics: (a) development of novel, bimetallic nanocatalyst PtIr/C and employing nanocatalyst in hydrogen peroxide oxidation reaction (HOPR). (b) Fabrication of the mini-biosensor with the homogeneous catalyst/enzyme composite structure by electrophoresis deposition (EPD) method. The crystalline and particle size of nanocatalyst were investigated by XRD and TEM, respectively. The catalytic activity was obtained by the amperometric determination of HOPR. The studies of synchrotron based- X ray absorption spectroscopy (XAS) and density functional theory (DFT) calculation demonstrated that the addition of Ir atom modify the d band electronic configuration of Pt atom and enhance the nanocatalyst functionality, consequently promote the HOPR activity. Furthermore, the HOPR mechanism on the catalyst surface has been proposed and the “deprotonation“step was considered to be rate determining step via this investigation. Moreover, EPD method has been employed to simultaneously deposit the nanocatalyst and enzyme onto the electrode surface. The depth profile analysis of ESCA provided the evidences that EPD method enables to create the homogeneous nanocatalyst/enzyme composite domain. The long term stability and the low value of Michaelis-Menten constant ( Kmapp =5.68 mM ) revealed that the composite matrix provide a stable and three dimensions structure. After the parameter optimization, the fabricated mini-biosensor showed a linear detection of glucose ranges from 2 mM to 20 mM with a detection limit of 0.1 mM and the maximal sensitivity of 2.89 μA/mM.cm2 (R2=0.995, R.S.D. =3.26%, N=3). Overall, EPD method has been used for fabricating the homogeneous nanocatalyst/enzyme composite mini-biosensor with favorable reproducibility, stability and accuracy.
CHANG, REN-WEN, and 張人文. "Study on structure and atomic distribution of Pt-Ag/C nano-sized bimetallic catalysts for CO oxidation." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/7qc285.
國立臺灣科技大學
化學工程系
94
In this work, a reduction method based on microwave reaction was used to synthesize Pt-Ag bimetallic catalysts in ethylene glycol solution. A step by step procedure was adopted to prepare Ptcore @ Agshell/C and Agcore @ Ptshell/C nano-sized bimetallic catalysts. By employing the X-ray Absorption Spectroscopy(XAS) and the extracted atomic structure parameters the structure of the bimetallic catalysts was analyzed. The relationship between the structure of the synthesize catalysts and activity toward CO oxidation. From the XRD analysis, the grain size of synthesized catalysts were about 1~3 nm wich is consistent with TEM observation. From XRD analysis, the Ag @ Pt/C catalysts with larger grain size exhibit a separated fcc structure, it was found that some of Agcore @ Ptshell/C catalysts were aggregated. In this work Temperature Programmed Surface Reaction (TPSR) was employed to evaluate the activity for CO oxidation and the electrochemical activity for CO stripping. The results show that the Pt-Ag/C-R1-1 catalyst shows the bast performance for CO oxidation. The Pt-Ag bimetallic catalysts were synthesized by changing the sequential procedure and the solution composition. The relationship between their structure and CO oxidation in both gas and liquid phase was established. The best structure of the synthesized catalyst for CO oxidation was found in this studty.
Chen, Hong-Jie, and 陳弘傑. "Electolysis-Enhanced Dispersed Nano Pd/Fe Bimetallic Particles Reduction Coupled with Persulfate Oxidation of Trichloroethylene from Groundwater - A Sandbox Test." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/6r7rsc.
國立屏東科技大學
環境工程與科學系所
103
In this study, electrolysis-enhanced dispersed permeable reactive barrier (PRB) packed with nano-scale palladium/iron (Pd/Fe) bimetallic particles coupling with persulfate were used to degrade trichlorethylene (TCE) in water The experiments were performed within a sand box. The experimental procedures were divided into five parts as follows: (1) characterization of nano-sacle Fe, nano-scale Pd/Fe, and dispersed nano-scale Pd/Fe, (2) test water quality analysis and adsorption test of TCE on quartz sand, (3) transport tests in porous media, (4) TCE degradation experiments with electrolysis- enhanced PRB packed with nano-sacle dispersed Pd/Fe, (5) TCE degradation experiments with electrolysis-enhanced PRB packed with nano-sacle dispersed Pd/Fe coupling with persulfate. The average specific surface area of dispersed nano-sized Pd/Fe (1:1000) particles was 167 m2/g. X-ray diffraction (XRD) analysis showed that the nano-sacle Pd/Fe particles had peaks at 2θ = 44.980 and 650 identified for Fe and 2θ = 27.450 and 31.880 for Pd, respectively. The ethane formed by TCE reduced by Fe was identified on dispered nano-scale Pd/Fe particles with a Fourier Transform Infrared Spectrometry (FTIR). TCE reduction using dispersed nano-sized Pd/Fe particles showed an increase in pH values and a decline in oxidation-reduction (redox) potential. The formation amount of chloride ions is proportional to the reduction amount of TCE in the reduction process. The persulfate oxidation test showed that the ferrous ions produced by the TCE reduction process with dispersed nano-scale Pd/Fe particles could activate persulfate to form sulfate radical (SO4-・) to further oxidize TCE. For the tests of electrolysis-enhanced PRB, the potential gradient set at 2 V/cm was better for TCE degradation than 1 V/cm. As the potential gradient was set at 2 V/cm, some phenomena were observed such as precipitates within the PRB and TCE evaporation by enormous amount of bubbles owing to the heat production. Therefore, the potential gradient 1 V/cm is the optimal parameter for following electrolysis tests. The results showed that TCE degradation by the treatment train of electrolysis-enhanced dispersed permeable reactive barrier (PRB) packed with nano-scale palladium/iron (Pd/Fe) bimetallic particles coupling with persulfate is feasible for remediation of groundwater contaminated by chlorinated solvents. Keywords: dispersion, persulfate, trichlorethylene, electrolysis,
Sinha, Shyam Kanta. "Synthesis and Transformation of AuCu Intermetallic Nanoparticles." Thesis, 2013. https://etd.iisc.ac.in/handle/2005/3407.
Sinha, Shyam Kanta. "Synthesis and Transformation of AuCu Intermetallic Nanoparticles." Thesis, 2013. http://etd.iisc.ernet.in/2005/3407.