Download or read book Synthesis and Characterization of Platinum Based Fuel Cell Catalysts written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of PT based Fuel Cell Catalysts written by Hee Soo Kim and published by . This book was released on 2004 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Platinum Based Catalysts for Fuel Cells written by Sonam Patel and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Platinum (Pt) and platinum alloys have attracted wide attention as catalysts to attain high performance to increase the power density and reduce the component cost of polymer electrolyte membrane fuel cells (PEMFCs). Extensive research has been conducted in the areas of new alloy development and understanding of mechanisms of electrochemical oxygen reduction reaction (ORR). The durability of PEMFCs is also a major barrier to the commercialization of these fuel cells. Recent studies have suggested that potential cycling can gradually lead to loss of active surface area due to Pt dissolution and nanoparticle grain growth [1]. In this thesis we report a one-step synthesis of highly-dispersed Pt nanoparticles and Pt- Cobalt supported on Ketjen carbon black (20% Pt/C & 20% Pt3Co/C) as electro-catalysts for PEMFCs. Pt particles with size in the range of ~ 2.6nm (Pt/C) and 3.9 nm (Pt3Co/C) were obtained through adsorption on carbon supports and subsequently thermal decomposition of platinum acetylacetonate (Pt(acac)2). A comparative characterization analysis, including X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), FT-iR, EDAX, cyclic voltammetry (CV), and oxygen reduction reaction (ORR) activity, was performed on the synthesized and commercial (46.5wt% TKK) catalysts. The analysis was to reveal the Pt dispersion on the carbon support, particle size and distribution, electrochemical surface area (ECA), and ORR activities of these catalysts. It was found that the synthesized Pt/C showed similar particle size to that of the TKK catalysts (2.6nm and 2.7nm, respectively), but narrower particle size distribution; while the particle size for Pt3Co/C was found to be ~3.9 nm. Accelerated durability tests (ADT) under potential cycles were also performed for Pt/C and TKK to study the electrochemical degradation of the catalysts in corrosive environments. The ADTs revealed that the two catalysts (Pt/C & TKK) were comparable with respect to degradation in ECA and ORR activities. Initial electrochemical evaluation of Pt3Co/C was conducted, but durability studies were not attempted in this thesis due to its worse ORR kinetics than those of the Pt/C catalyst. From the experimental data, it was found that particle size impacted negatively the ECA and ORR activity of the catalysts.

Download or read book PEM Fuel Cell Electrocatalysts and Catalyst Layers written by Jiujun Zhang and published by Springer Science & Business Media. This book was released on 2008-08-26 with total page 1147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proton exchange membrane (PEM) fuel cells are promising clean energy converting devices with high efficiency and low to zero emissions. Such power sources can be used in transportation, stationary, portable and micro power applications. The key components of these fuel cells are catalysts and catalyst layers. “PEM Fuel Cell Electrocatalysts and Catalyst Layers” provides a comprehensive, in-depth survey of the field, presented by internationally renowned fuel cell scientists. The opening chapters introduce the fundamentals of electrochemical theory and fuel cell catalysis. Later chapters investigate the synthesis, characterization, and activity validation of PEM fuel cell catalysts. Further chapters describe in detail the integration of the electrocatalyst/catalyst layers into the fuel cell, and their performance validation. Researchers and engineers in the fuel cell industry will find this book a valuable resource, as will students of electrochemical engineering and catalyst synthesis.

Download or read book Synthesis and Characterization of Platinum based Multi component Catalysts for Direct Methanol Fuel Cells written by Li Ren and published by . This book was released on 2007 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In the thesis work, Pt-based binary, ternary, quaternary alloy anode catalysts supported on sonochemically treated multi-walled carbon nanotubes (CNTs) were synthesized with ethylene glycol reduction of corresponding metal chloride salts. Inductively coupled plasma-mass spectroscopy (ICP-MS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were used for catalyst characterization. Cyclic voltammetry for methanol oxidation and CO stripping were used to evaluate the performance of the catalysts. PtRu nanoparticles supported on CNTs (PtRu/CNT) were prepared under a series of pHs. It was found that the PtRu particle size, composition, and catalytic activity were all sensitive to the deposition pHs. CO stripping results provided the peak potential and active surface area for each catalyst. The atomic ratios tended to approach the predetermined ratio 1:1 with the increase of pH, which is favored by bi-functional catalytic mechanism. PtRu catalysts prepared at higher pHs presented better electrochemical activity toward methanol oxidation. Humidified oxygen treatment of the PtRu/CNT led to improved activity of the catalysts toward methanol electro-oxidation, implying that Ru hydroxide is better than Ru as a co-catalyst. PtRu, PtOs, PtRuOs, and PtRuOsIr nanoparticles supported on CNTs with atomic ratios of Pt:Ru (tr:46), Pt:Os (80:20), Pt:Ru:Os (54:36:10), and Pt:Ru:Os:Ir (44:36:10:5) were prepared. Cyclic voltammetry for the methanol oxidation and CO stripping at the catalysts showed that PtRu/CNT and PtRuOsIr/CNT have the best performance toward methanol oxidation, PtRuOs/CNT has the lowest activity, but PtOs/CNT exhibits better catalytic activity only at potential or 0.73 V"--Abstract, leaf iii.

Download or read book Nanostructured Catalyst Systems for Fuel Cells written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project is to synthesize and characterize new O2 reduction catalysts with enhanced activity and ultra low Pt loading, and to test them in membrane electrode assemblies (MEAs) to determine their performance under fuel cell cathode operating conditions.

Download or read book Synthesis and Characterization of Non PGM Catalysts for Fuel Cell Applications written by Sudharsan Sridhar and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuel Cells convert the chemical energy of a fuel and an oxidizing agent into electricity through a pair of redox reactions. Proton Exchange Membrane (PEM) fuel cells convert (efficiency-60%) hydrogen and air to power the electric motors with zero emissions, facilitating the development of environmentally friendly and sustainable automobile technologies. One of the major obstacles for larger commercial viability of Fuel Cells for automobile applications is their cost-effectiveness. Currently, fuel cells use platinum as a catalyst material, which is prohibitively expensive for commercial automobile applications. The development of non-Platinum Group Metal (non-PGM) catalyst materials with similar electrochemical performance to that of Platinum is essential for adopting fuel cells in automobile technologies in a big way. Hence, this research focused on the synthesis and characterization of three different non-PGM catalyst materials based on graphene and graphene oxide with nitrogen and Zeolite Imidazole Frameworks (ZIF) and an additional transition metal (Fe) loading. Various characterization techniques were performed to analyze the chemical, morphological, and electrochemical properties of each of these synthesized materials. The synthesized catalyst materials are N-GR-ZIF, N-RGO-ZIF, and N-RGO-Fe-ZIF with varying nitrogen doping. N-RGO-Fe-ZIF exhibited electrochemical characteristics that are quite comparable to that of Pt-based catalysts. The details of the synthesis process and characterization of the synthesized materials are discussed in this dissertation.

Download or read book Synthesis and Characterization of Platinum based Ternary Nanoparticles for Fuel Cell Applications written by Daniel Adrion and published by . This book was released on 2018 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis Characterization and Analysis of Platinum based Multiphase Catalysts for Direct Ethanol Fuel Cells written by Jonathan R. Mann and published by . This book was released on 2006 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Platinum-based particles are synthesized via the polyol process in an effort to include various metal oxides in a multi-phase catalyst for the direct ethanol fuel cell anode. Among Eu, In, La and Nb, no single metal oxide with platinum yields open circuit potentials or maximum current densities as high as tin oxide with platinum. For this reason, particles with platinum, tin oxide and the oxide of a third metal were developed. Platinum tin/indium oxide slightly outperforms platinum tin oxide. The particles are characterized by TEM, EDX, XRD and ICP. The metal oxides and the platinum are located together in one particle, uniformly 5.3 nm in diameter. ICP analysis indicates that the catalysts are 20% platinum on carbon and the metals of the oxides are on the order of 1-2% by mass. The catalytic abilities of the particles were evaluated in a single cell direct ethanol fuel cell where polarization curves were taken up to 130°C, and oxidation products were analyzed by gas chromatography. Open circuit voltages of as high as 0.82 V were obtained for platinum tin/indium oxide catalysts and current densities as high as 0.4 A cm-2 were seen. The cells produced large amounts of acetaldehyde and acetic acid, as well as small amounts of methanol and carbon dioxide. A spillover mechanism is proposed for the oxidation of ethanol to CO2 on these platinum/metal oxide catalysts.

Download or read book Synthesis and Characterization of CO and H2S Tolerant Electrocatalysts for PEM Fuel Cell written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H2-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO in the H2-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loading and improve the PEMFC performance, we have synthesized a number of Pt-based binary, ternary, and quaternary electrocatalysts using Ru, Mo, Ir, Ni, and Co as a substitute for Pt. Co-catalytic activities were found for the elements Mo, Ru, and Ir. Both the ternary (Pt/Ru/Mo/C) and quaternary (Pt/Ru/Mo/Ir/C) metal catalysts in membrane electrode assemblies (MEA) outperformed pure Pt/C catalysts at all levels in presence of CO up to 100 ppm. Preliminary results suggest that by substituting Mo, Ru, and Ir in catalyst formulation, it is possible to reduce Pt-loading and increase CO-tolerance in PEMFC application. Comparison studies showed that the newly developed ternary and quaternary catalysts with lower Pt outperformed pure Pt catalyst in presence of CO-contaminated H2 fuel. High performance at low Pt loading of less than 0.4 mg/cm2 was achieved, thus exceeding the initial targets.

Download or read book Synthesis and Characterization of Pt TiO2 C Composite Catalysts for Fuel Cells Prepared Using a Glucose Modifier written by Christopher Odetola and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysts in the electrodes of polymer exchange membrane fuel cells (PEMFCs) serve a critical function in reactions which can be used to generate electrical energy from chemical fuels. Pt nanoparticles are commonly dispersed on a conductive support and used as electrode materials in these devices because of their exceptional catalytic activity and electrochemical active surface area. The performance and stability of these electrodes strongly depend on the characteristics of the support. Catalysts supported on high surface area carbon black are widely used in low-temperature fuel cells. In PEMFCs, these catalyst materials can be exposed to high potential and low pH values, resulting in irreversible loss of activity that will limit the useful lifetime of the cell, ultimately leading to its failure. Pt is a noble metal which has good intrinsic stability, but carbon is not thermodynamically stable resulting in the corrosion of the catalyst support under these conditions. The design of more resilient platinum catalyst supports to carry out the successful reaction in a fuel cell's catalyst layer is required to extend the lifetime of PEMFCs degradation. In this thesis, two approaches were used to synthesize robust catalyst support materials for fuel cell applications. In the first case, carbon surfaces were functionalised to enhance their interactions with the catalyst and secondly, stable metal oxide was combined with modified carbon substrates, to maximise contacts within the composite electrocatalysts and to prevent carbon corrosion of a single phase carbon support catalyst. TiO2 NPs, were first chemically bonded to the surfaces of Vulcan carbon to help anchor the Pt catalyst nanoparticles through strong metal-support interactions. Validation of a dual phase catalyst support is an important goal of this research. Each material phase offers a unique advantage that can only be recognized by the preparation of a composite electrocatalyst. Pristine Vulcan (PV) was functionalised with glucose hydroxyl functional groups that react with the base titanium metal alkoxide in a sol-gel reaction and then calcined to form a more chemically crystalline surface. This is followed by impregnation reduction process to deposit the nanostructured Pt catalyst. Material characterization data of synthesized materials were used to correlate the effects of support structure and composition on resilient performance. Advantages from the TiO2/C supports toward performance and durability were contrasted against a set of control samples and demonstrated ex situ. The prepared composite catalysts showed substantial enhancements toward oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) as well as improved stability of the Pt-TiO2 heterogeneous interface formed between catalyst and support. The enhanced performance and durability of these composite catalysts is improved by applying the science of materials and interfaces to the synthesis of composite supports, thus serving as an example for further progress and optimization. Irradiation of these composite catalysts with UV-visible light also showed ~ 171 % photo enhanced activity for MOR, which clearly demonstrates a synergistic effect between the photo- and electrocatalysts. The comparison between the prepared catalysts indicates that there is an appropriate ratio of carbon and TiO2 to obtain the best performance of these photoelectroactive materials. These results demonstrate that methanol oxidation is achieved by electro- and photoelectrocatalysis using a simple and affordable method. This procedure can be conveniently exploited to enhance the response of direct methanol fuel cell electrodes.

Download or read book Synthesis and Characterization of Binary and Ternary Platinum Alloy Catalysts for Direct Methanol Fuel Cell Application written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SYNTHESIS AND CHARACTERIZATION OF CO AND H sub 2 S TOLERANT ELECTROCATALYSTS FOR PEM FUEL CELL written by Shamsuddin Ilias and published by . This book was released on 2005 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H{sub 2}-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H{sub 2}S in the H{sub 2}-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loading and improve the PEMFC performance, we propose to synthesize a number of Pt-based binary, ternary, and quaternary electrocatalysts using Ru, Mo, Ir, Ni, and Co as a substitute for Pt. By fine-tuning the metal loadings and compositions of candidate electrocatalysts, we plan to minimize the cost and optimize the catalyst activity and performance in PEMFC. The feasibility of the novel electrocatalysts will be demonstrated in the proposed effort with gas phase CO and H{sub 2}S concentrations typical of those found in reformed fuel gas with coal/natural gas/methanol feedstocks. During this reporting period several tri-metallic electrocatalysts were synthesized using both ultra-sonication and conventional method. These catalysts (Pt/Ru/Mo, Pt/Ru/Ir, Pt/Ru/W, Ptr/Ru/Co, and Pt/Ru/Se on carbon) were tested in MEAs. From Galvonstatic study the catalytic activity was found in the order of: Pt/Ru/Mo/C> Pt/Ru/Ir/C> Pt/Ru/W/C> Ptr/Ru/Co/C> and Pt/Ru/Se. It appears that electrocatalysts prepared by ultra-sonication process are more active compared to the conventional technique. Work is in progress to further study these catalysts for CO-tolerance in PEMFC.

Download or read book Synthesis and Characterization of Pt and Pt Co Catalysts for Polymer Electrolyte Membrane Fuel Cells written by Min Chen and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Synthesis of high performance catalysts is one of the tasks for fuel cell researchers. In this thesis work, carbon supported Pt and Pt-Co alloy catalysts were prepared by several improved methods. Thermal gravity analysis (TGA), transmission electron microscope (TEM), and X-ray diffraction (XRD) were used to characterize these catalysts. Electrochemical activities of the catalysts were measured by cyclic voltammetry (CV) and oxygen reduction reaction (ORR)"--Abstract, leaf iii.

Download or read book Non Noble Metal Fuel Cell Catalysts written by Zhongwei Chen and published by John Wiley & Sons. This book was released on 2014-04-03 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written and edited by top fuel cell catalyst scientists and engineers from both industry and academia, this is the first book to provide a complete overview of this hot topic. It covers the synthesis, characterization, activity validation and modeling of different non-noble metal electrocatalysts, as well as their integration into fuel cells and their performance validation, while also discussing those factors that will drive fuel cell commercialization. With its well-structured approach, this is a must-have for researchers working on the topic, and an equally valuable companion for newcomers to the field.

Download or read book Design Synthesis and Characterization of Fuel Cell Electrocatalysts for the Direct Oxidation of Organic Fuels written by Aurora Marie Cabrera Fojas and published by . This book was released on 2008 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis Characterization and Design of Novel Fuel Cell Electro oxidation Catalysts written by Aurora Marie Cabrera Fojas and published by . This book was released on 2004 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: