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 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 Synthesis and Characterization of Nanoalloys and Non precious Metal Catalysts for Energy and Environmental Applications written by Heather Marie Barkholtz and published by . This book was released on 2016 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two major project areas are reported in this work. First, a new lithium-assisted dissolution-alloying nanoalloy synthesis technique will be introduced. The development of a new nanoalloy synthesis method is desirable to circumvent issues with traditional co-reduction of metal salt methodology. Co-reduction of metal salts can result in unintended core-shell formation due to different metal ion reduction potentials, as well as oxidation of one component resulting in dealloying of the material when it is exposed to air. In order to best address these issues with a new technique, Pd3Ag, PdPt, and PdZn systems were studied because Pd3Ag and PdPt tend to form core-shell structures while PdZn is incredibly difficult to synthesize due to the propensity of Zn to oxidize. The metal nanoalloy systems described in this work (Pd 3Ag, PdPt, and PdZn) were prepared by directly dispersing individual bulk metal alloys (Pd3Ag) or individual bulk metals (Pd, Pt, and Zn) into molten lithium to form an atomic metal dispersion. The lithium melt is then cooled, removed from the glove box, and converted to LiOH, which allows for the metal atoms to self-assemble into nanoalloys. Alloy structure and nanoscale size were confirmed via XRD, TEM, EXAFS, and XANES methods. The catalytic activity of the Pd3Ag system was investigated towards the hydrogenation of acrolein, and the PdPt system was used for methanol electro-oxidation. Both Pd3Ag and PdPt nanoalloy systems gave substantial improvements in their respective catalytic applications over a Pd or Pt standard, respectively. The next project focuses on the rational design and preparation of metal-organic framework (MOF)-derived electrocatalyst materials for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). MOF-derived electrocatalysts are non-platinum group metal (non-PGM) materials and are leading candidates for transportation applications due to their low cost, relatively low operating temperature, capacity to achieve high power density, and direct conversion of chemical to electrical energy acting to improve fuel utilization efficiency. Cathodic ORR is typically sluggish compared to the anodic hydrogen oxidation reaction, requiring more catalyst material to achieve comparable performance. Therefore, research into non-PGM catalysts focuses on the cathodic material design and activation. In this part of the dissertation the focus is to tackle the aggressive milestones set by the U.S. Department of Energy for non-PGM catalysts. First, a series of investigations into the effect of different iron additives and carbon additives on the ORR performance and electrode characteristics was carried out using a one-pot all solid-state synthesis technique to prepare ZIF-8 materials. ZIF-8 is a specific type of MOF which has a Zn2+ metal center bonded to two 2-methylimidazole ligands, forming a three-dimensional matrix with high surface area. After the ZIF-8 was prepared, it was ball milled, pyrolyzed, acid washed, and thermally activated once again in a NH3 environment to yield ORR electrocatalysts consisting of an iron and nitrogen-doped carbon (Fe-N-C) morphology. This one-pot all solid-state synthesis method also allows for investigation into the effect of changing 2-methylimidazole to imidazole on the ORR activity. The effect of this change was determined through catalyst morphology and component characterization and well and electrochemical methods. Finally, ZIF-8 synthesized by wet chemistry was used to prepare the same type of Fe-N-C material as described above. A simple method of tailoring the surface structure and porosity is introduced through careful control of the time spent in NH3 environment. NH3 serves to etch the surface of the material as a function of time spent, which results in widening of pores and removal of surface atoms. Careful control and optimization of NH3 activation conditions allowed for significant improvements in ORR activity in a single fuel cell. Finally, the impact of triple phase boundary penetration on air fed fuel cell data was investigated. Furthermore, it was discovered than when air is used as the oxidant fuel, a break-in period of catalyst improvement exists during the first few polarization curves. It is proposed that scanning to high currents produces water in microporous areas, wetting Nafion ionomer and including those areas in the TPB network.

Download or read book Synthesis and Characterization of Carbon Catalyst Substrates for Fuel Cell Applications written by Ashley Dawn Moore and published by . This book was released on 2011 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization and Optimization of Carbon Based Electrocatalysts and Supports for Fuel Cell Applications written by Abhinav Poozhikunnath and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of expensive platinum-based catalysts has been a major obstacle for the widespread use of low temperature fuel cells. As a result, there is significant commercial and scientific interest in replacing platinum-based electrocatalysts with cost-effective alternatives of comparable performance. This thesis explores the process-structure-property relationship of platinum group metal-free (PGM-free), metal-nitrogen-doped carbon (M-N-C) electrocatalysts for oxygen reduction synthesized by a flame spray pyrolysis process called Reactive Spray Deposition Technology (RSDT). Metal-Nitrogen-Carbon (M-N-C) type Platinum Group Metal-free (PGM-free) electrocatalyst, synthesized directly from liquid solution precursors by the partial combustion of organic material in the RSDT flame. Central to this work is the modification of the RSDT for carbon synthesis using liquid aromatic hydrocarbon-based precursors. The direct synthesis of the M-N-C electrocatalysts using an open atmosphere flame spray pyrolysis technique, has not been reported previously and offers a scalable alternative to the energy-intensive, multi-step furnace-based processes that are conventionally used for synthesizing M-N-C catalysts. The physical and chemical characteristics of the synthesized material are examined and the performance of the catalyst with respect to RSDT process parameters such as precursor composition and fuel equivalence ratio are analyzed with an aim of preparing the groundwork for further development of the synthesis process. The baseline Fe-N-C catalyst synthesized by RSDT exhibits activity towards oxygen reduction in alkaline media and shows excellent dynamic stability even after 4000 potential cycles. Based on these results, additional efforts needed to optimize the RSDT process parameters to improve catalyst activity and for mass-producing M-N-C electrodes are also discussed. As a second subject, this thesis also investigates an application of multi-scale correlative characterization in quality control of carbon black for fuel cell and battery applications. A workflow using correlative characterization techniques including X-CT, laser-milling and elemental analysis is described. Potential failure modes are discussed based on the properties of the impurities analyzed and a case is made for the use of correlative characterization for establishing standards of quality control in commercially produced fuel cell and battery components.

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 Electrocatalysis for Membrane Fuel Cells written by Nicolas Alonso-Vante and published by John Wiley & Sons. This book was released on 2023-12-11 with total page 581 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrocatalysis for Membrane Fuel Cells Comprehensive resource covering hydrogen oxidation reaction, oxygen reduction reaction, classes of electrocatalytic materials, and characterization methods Electrocatalysis for Membrane Fuel Cells focuses on all aspects of electrocatalysis for energy applications, covering perspectives as well as the low-temperature fuel systems principles, with main emphasis on hydrogen oxidation reaction (HOR) and the oxygen reduction reaction (ORR). Following an introduction to basic principles of electrochemistry for electrocatalysis with attention to the methods to obtain the parameters crucial to characterize these systems, Electrocatalysis for Membrane Fuel Cells covers sample topics such as: Electrocatalytic materials and electrode configurations, including precious versus non-precious metal centers, stability and the role of supports for catalytic nano-objects; Fundamentals on characterization techniques of materials and the various classes of electrocatalytic materials; Theoretical explanations of materials and systems using both Density Functional Theory (DFT) and molecular modelling; Principles and methods in the analysis of fuel cells systems, fuel cells integration and subsystem design. Electrocatalysis for Membrane Fuel Cells quickly and efficiently introduces the field of electrochemistry, along with synthesis and testing in prototypes of materials, to researchers and professionals interested in renewable energy and electrocatalysis for chemical energy conversion.

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 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 Single Atom Catalysts written by Prashanth W. Menezes and published by Elsevier. This book was released on 2024-01-22 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single Atom Catalysts: Design, Synthesis, Characterization, and Applications in Energy focuses on the synthesis, design and advanced characterization techniques for single atom catalyst materials and their direct energy conversion and storage applications. This book reviews emerging applications of single atom catalysts in fuel cells, batteries, water splitting, carbon dioxide reduction, and nitrogen fixation. Both noble metal and non-noble metal single atom catalysts (SACs) are discussed as noble metal-based SACs are highly efficient and non-noble metal-based SACs might have lower associated costs. There is an emphasis on materials design focused on improving performance of catalysts based on overall catalytic activity, selectivity and stability. Specific parameters that impact this performance are emphasized throughout the book, including single metal atom stabilization, metal-support interactions and the coordination environment. Discusses the different intricate design and synthesis methods pertaining to various noble and non-noble metal-based SACs Provides in-depth understanding about the structural, morphological, and physicochemical characterization techniques of synthesized SACs with data analysis and interpretation Describes state-of-the-art applications of SACs in renewable energy generation and their conversion, storage, and associated challenges

Download or read book Low Platinum Group PGM Metal Catalysts Cooperative Research and Development Final Report CRADA Number CRD 16 649 written by and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High catalyst loadings and relatively high over-potential losses have limited the commercial viability of direct methanol fuel cells (DMFCs). Platinum-based catalysts are used in DMFCs with a loading of 4.5 mg cm-2; the catalyst layer is a significant contributor to the membrane electrode assembly (MEA) cost, which accounts for 60% of the system cost. The large-scale commercial viability of DMFCs is dependent on a significant (~50%) cost reduction. If these cost goals can be reached, the current market can be extended from 100's of units to 10,000's of units. Currently, Oorja is using a platinum-ruthenium catalyst for methanol oxidation, but does not have access to a supplier able to develop low-platinum group (PGM) metal catalysts to reach DMFC cost reduction targets. Oorja has recently developed a small lab scale capability in fabrication and testing of DMFC membrane electrode assemblies (MEAs), but does not have access to synthesis and characterization of advanced electrocatalysts. The materials, equipment, and expertise at the National Renewable Energy Laboratory (NREL) are of significant value to Oorja. NREL recently develop platinum-nickel nanowires as catalysts in hydrogen fuel cells. These materials have also shown promise in DMFC applications as a potential replacement for standard platinum-ruthenium catalysts; in ex-situ testing, these materials have shown one order of magnitude higher mass activity and can avoid ruthenium crossover contamination effects. These combined properties are exceptionally appealing to Oorja, and can result in significantly decreasing the capital costs of DMFCs.

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:

Download or read book Synthesis and Characterization of Electrocatalyst Libraries for PEM Fuel Cells written by Kousik Ganesan and published by . This book was released on 2005 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conversion of energy stored in renewable fuels for sustained and environment friendly operation necessitates new technologies. Polymer electrolyte membrane fuel cells represent an energy conversion technology that has advantages of high operating efficiencies with low hazardous emissions. However the discovery of more active and poison tolerant catalysts for anode and cathode reactions remains a major barrier to commercialization of this technology. The search for improved catalyst formulations is hindered by the massive parameter space available for their construction. Combinatorial methods represent an exploration process well suited to accelerate this discovery through the ability to generate and screen a multitude of compositions in a single experiment. In this work, we describe a combinatorial strategy to generate a wide variety of catalyst compositions (single/binary) and interrogate their activity directly in an electrochemical environment. Catalyst library fabrication tools based upon array deposition methods were used to prepare samples possessing catalyst combinations containing Pt and additional metals such as Ru, Rh, Mo, Ir, Nb, Ta, Pd, Sn, Os and W. High throughput screening of catalytic activity was accomplished by scanning electrochemical microscopy (SECM). Reactivity maps were constructed by directly measuring the kinetics of hydrogen oxidation with a scanning microelectrode probe in the presence and absence of adsorbed carbon monoxide. Results provide quantitative rate constants for hydrogen oxidation and poison tolerance over a broad sampling of catalyst compositions.

Download or read book Direct Methanol Fuel Cells written by Antonio Salvatore Aricò and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with an analysis of materials issues, status of technologies and potential applications of direct methanol fuel cells. The principle of operation of direct methanol fuel cells and the status of knowledge in the basic research areas are presented. The technology of direct methanol fuel cells is discussed in this book with particular regard to fabrication methodologies for the manufacturing of catalysts, electrolytes membrane-electrode assemblies, stack hardware and system design.

Download or read book Synthesis and Characterization of Nanostructured Carbon Supported Pt based Electrocatalysts written by Geng, Xi and published by . This book was released on 2012 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Fuel cell, as an alternative green power source for automobiles and portable electronics, has attracted worldwide attention due to its desirable properties such as high energy density and low greenhouse gas emission. Despite great progress in the past decades, several challenges still remain as obstacles for the large-scale commercialization. Among them, the high cost of Pt-based electrode material is considered as a major barrier, while the life span or stability of electrode catalysts is another concern since the electrocatalysts can be easily poisoned during the fuel cell operation. In order to overcome these issues, nanostructured carbon materials, especially carbon nanotubes (CNTs), are studied as catalyst support. In addition, recent research also suggests that the coupling of a second metal element with Pt can effectively protect the electrocatalysts from being poisoned and thus improve their long-term durability. The objective of the present work was to demonstrate an efficient synthetic method for the preparation of CNTs supported binary PtM (M=Ru, Sn) electrocatalysts. In this project, a polymer wrapping technique along with an in-situ polyol reduction strategy was adopted to decorate well-dispersed binary PtM nanoparticles on the surface of modified-CNTs. The unique nanostructures as well as the excellent catalytic activities of the as-prepared nanohybirds were investigated through a diversity of physiochemical and electrochemical characterization techniques. This fabrication method provided a simple and convenient route to assemble Pt-based catalyst on carbon substrates, which is useful for the further development of high-performance fuel cell catalysts.

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 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.