Download or read book Optimization of Ultra low Loading Catalyst Layers for Pemfc and Pemwe Using Reactive Spray Deposition Technology written by Haoran Yu and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The optimization of low catalyst loading electrode fabricated with reactive spray deposition technology (RSDT) is conducted for proton exchange membrane fuel cell (PEMFC) and proton exchange membrane water electrolyzer (PEMWE) applications. For PEMFC, the key catalyst layer parameters studied in this work include: ionomer-to-carbon (I/C) ratio, platinum particle size, and platinum loading on carbon. The RSDT-derived catalyst layers were shown to exhibit better ionomer coverage on the carbon support than traditional fabrication method, reducing the amount of ionomer needed for optimal fuel cell performance. Analysis on the fuel cell polarization sources for RSDT-derived catalyst layer was performed to further elucidate the influence of I/C ratio on the oxygen reduction reaction (ORR) activity and oxygen transport. The effect of platinum particle size and platinum loading on carbon were studied by employing two types of gradient cathode to mitigate platinum dissolution and migration to the electrolyte membrane. One type of the gradient cathode was made with platinum particle size of 5 nm near the membrane and platinum particle size of 2 nm toward the GDL. The platinum loading on carbon was kept constant at 40 wt% throughout the cathode. The other type of gradient cathode kept the platinum particle size of 2 nm throughout the cathode but used higher platinum loading on carbon (60 wt%) near the membrane and 40 wt% platinum toward the GDL. Accelerated stress test was performed using triangular wave potential cycling from 0.6V to 1.0V at 50 mV s-1for 30,000 cycles. The degradation mechanism was investigated using cross-sectional transmission electron microscopy (TEM). Durable anode catalyst layer for PEMWE was developed with an IrOx/Nafion composite thin film with the key catalyst layer parameters being the surface oxidation state of iridium and the homogeneity of the catalyst layer. The oxide rich iridium showed superior oxygen evolution reaction (OER) activity and higher catalyst stability in electrolyzer test. In addition, the catalyst layer homogeneity played an important role in the catalyst stability. The optimized electrolyzer durability achieved ~1400 hours with ~0.08 mg cm-2 iridium loading, more than 90% reduction compare to the commercial catalyst.
Download or read book Pore scale Simulation of Cathode Catalyst Layers in Proton Exchange Membrane Fuel Cells PEMFCs written by Weibo Zheng (Ph. D. in mechanical engineering) and published by . This book was released on 2019 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the complex phenomena occurring inside the catalyst layer of a proton exchange membrane fuel cell (PEMFC) is critical to design of an optimized structure with low platinum loading and high performance. Describing detailed physical and chemical processes in the catalyst layer at the resolution of pore scale, pore-scale simulation is considered as a promising approach for use in understanding the structure-performance relation and subsequent optimization of the catalyst layer. For wide spread use in industry, the computational cost of pore-scale simulation needs to be reduced. To achieve this goal, a multiscale decomposition method that accelerates the convergence of an iteratively-solved variable distribution in porous electrodes is proposed. The multiscale method combines the macroscopic method with pore-scale simulation by decomposing a variable distribution into the macroscopic component and local fluctuations. The decomposition removes the slowly converged, long wavelength components in an iteratively-solved variable distribution, thereby accelerating the convergence. In this research, to reduce the computational cost of multiphase pore-scale simulation, the multiscale method is applied to the electrolyte phase potential and oxygen concentration, both of which converge slowly and limit the overall computational efficiency. The results show that the multiscale method can substantially accelerate the convergence without sacrificing the accuracy. It is also found that the estimation of the effective transport property appearing in the volume-averaged part of the multiscale method influences the convergence rate of the multiscale method. With more accurate estimation of an effective transport property, the multiscale method is shown to work more effectively, especially for a thick porous electrode. Being an important parameter in the application to oxygen concentration, the effective oxygen diffusivity in pores is systematically investigated using pore-scale simulation, and empirical correlations for use in the multiscale method, as well as other macroscopic simulation methods, are obtained. The emphasis is placed on the importance of Knudsen diffusion in nanoscale pores in the catalyst layer. The results also highlight the importance of liquid water distribution on the effective diffusivity estimation and, therefore, on the computational efficiency of the multiscale method. With reduced computational cost, multiphase pore-scale simulation of a catalyst layer used in a laboratory experiment is successfully performed. The proposed multiscale decomposition method can be extended to pore-scale simulation for any porous electrodes.
Download or read book Improved Cathode Catalyst Performance in PEM Fuel Cells written by Kurt Owen Jensen and published by . This book was released on 2010 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PEM Water Electrolysis written by Dmitri Bessarabov and published by Academic Press. This book was released on 2018-07-23 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen Energy and Fuel Cell Primers is a series of concise books that present those coming into this broad and multidisciplinary field the most recent advances in each of its particular topics. Its volumes bring together information that has thus far been scattered in many different sources under one single title, which makes them a useful reference for industry professionals, researchers and graduate students, especially those starting in a new topic of research. These volumes, PEM Water Electrolysis vol 1 and 2, allows these readers to identify the technology gaps for the development of commercially viable PEM electrolysis systems for energy applications. This primer examines the fundamentals of PEM electrolysis and selected research topics that are currently subject of attention by academic and industry community, such as gas cross-over and AST protocols. This lays the foundation for the exploration of the current industrial trends for PEM electrolysis, such as power to gas application, are discussed, with strong focus on the current trends in the application of PEM electrolysis associated with energy storage. These include durability aspects of PEM electrolysis systems and components, accelerated stress test protocols, manufacturing aspects of large-scale electrolyzers and components, gas crossover problems in PEM electrolyzer safety, and challenges associated with high-current density operation of PEM electrolyzers. A technology development matrix for systems and components requirements will also be covered, as well as unconventional PEM water electrolysis systems, such as ozone generators Presents the fundamentals and most current knowledge in proton exchange membrane water electrolyzers Explores the technology gaps and challenges for commercial deployment of PEM water electrolysis technologies Includes unconventional systems, such as ozone generators Brings together information from many different sources under one single title, making it a useful reference for industry professionals, researchers and graduate students alike
Download or read book Electrocatalysis written by Minhua Shao and published by Springer. This book was released on 2021-03-21 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry Collections presents critical reviews from the journal Topics in Current Chemistry organized in topical volumes. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience.Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field.
Download or read book PEM Fuel Cell Diagnostic Tools written by Haijiang Wang and published by CRC Press. This book was released on 2011-08-25 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: PEM Fuel Cell Diagnostic Tools presents various tools for diagnosing PEM fuel cells and stacks, including in situ and ex situ diagnostic tools, electrochemical techniques, and physical/chemical methods. The text outlines the principles, experimental implementation, data processing, and application of each technique, along with its capabilities and
Download or read book Hydrogen Based Energy Conversion written by Jin-Soo Park and published by MDPI. This book was released on 2021-04-28 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of the nine sections: i) the first three sections are related to polymeric electrolyte composites; ii) the next two sections relate to gas diffusion layers (GDLs); iii) the next two sections relate to membrane¬–electrode assembly (MEA); iv) and the final two sections deal with the numerical simulation of flow fields for polymer electrolyte fuel cells (PEFCs). All sections describe recent results of the study of the main components of PEFC stacks. The studies provide the underlying material, electrochemical, and/or mechanical aspects that enhance the mass transport of gas, ions (liquid), and electrons for a better performance of PEFCs and the electrochemical reactions at the triple-phase boundary in electrodes. Each study offers the fundamentals, a comprehensive background, and cutting-edge technology on the aforementioned materials and mass transport phenomena.
Download or read book Hydrogen Batteries and Fuel Cells written by Bengt Sundén and published by Academic Press. This book was released on 2019-07-02 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen, Batteries and Fuel Cells provides the science necessary to understand these important areas, considering theory and practice, practical problem-solving, descriptions of bottlenecks, and future energy system applications. The title covers hydrogen as an energy carrier, including its production and storage; the application and analysis of electrochemical devices, such as batteries, fuel cells and electrolyzers; and the modeling and thermal management of momentum, heat, mass and charge transport phenomena. This book offers fundamental and integrated coverage on these topics that is critical to the development of future energy systems. Combines coverage of hydrogen, batteries and fuel cells in the context of future energy systems Provides the fundamental science needed to understand future energy systems in theory and practice Gives examples of problems and solutions in the use of hydrogen, batteries and fuel cells Considers basic issues in understanding hydrogen and electrochemical devices Describes methods for modeling and thermal management in future energy systems
Download or read book Advances in Hydrogen Energy written by Catherine E. Grégoire Padró and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the future, our energy systems will need to be renewable and sustainable, efficient and cost-effective, convenient and safe. Hydrogen has been proposed as the perfect fuel for this future energy system. The availability of a reliable and cost-effective supply, safe and efficient storage, and convenient end use of hydrogen will be essential for a transition to a Hydrogen Economy. Research is being conducted throughout the world for the development of safe, cost-effective hydrogen production, storage, and end-use technologies that support and foster this transition. This book is a collection of important research and analysis papers on hydrogen production, storage, and end-use technologies that were presented at the American Chemical Society National Meeting in New Orleans, Louisiana, USA, in August 1999.
Download or read book Solar Hydrogen Production written by Francesco Calise and published by Academic Press. This book was released on 2019-08-15 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar Hydrogen Production: Processes, Systems and Technologies presents the most recent developments in solar-driven hydrogen generation methods. The book covers different hydrogen production routes, from renewable sources, to solar harvesting technologies. Sections focus on solar energy, presenting the main thermal and electrical technologies suitable for possible integration into solar-based hydrogen production systems and present a thorough examination of solar hydrogen technologies, ranging from solar-driven water electrolysis and solar thermal methods, to photo-catalytic and biological processes. All hydrogen-based technologies are covered, including data regarding the state-of-the art of each process in terms of costs, efficiency, measured parameters, experimental analyses, and demonstration projects. In the last part of the book, the role of hydrogen in the integration of renewable sources in electric grids, transportation sector, and end-user applications is assessed, considering their current status and future perspectives. The book includes performance data, tables, models and references to available standards. It is thus a key-resource for engineering researchers and scientists, in both academic and industrial contexts, involved in designing, planning and developing solar hydrogen systems. Offers a comprehensive overview of conventional and advanced solar hydrogen technologies, including simulation models, cost figures, R&D projects, demonstration projects, test standards, and safety and handling issues Encompasses, in a single volume, information on solar energy and hydrogen systems Includes detailed economic data on each technology for feasibility assessment of different systems
Download or read book Polymer Electrolyte Fuel Cells written by Alejandro A. Franco and published by CRC Press. This book was released on 2013-07-09 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the recent research progress on the fundamental understanding of the materials degradation phenomena in PEFC, for automotive applications. On a multidisciplinary basis, through contributions of internationally recognized researchers in the field, this book provides a complete critical review on crucial scientific topics related to PEFC materials degradation, and ensures a strong balance between experimental and theoretical analysis and preparation techniques with several practical applications for both the research and the industrial communities.
Download or read book Introduction to Corrosion Science written by E. McCafferty and published by Springer Science & Business Media. This book was released on 2010-01-04 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook is intended for a one-semester course in corrosion science at the graduate or advanced undergraduate level. The approach is that of a physical chemist or materials scientist, and the text is geared toward students of chemistry, materials science, and engineering. This textbook should also be useful to practicing corrosion engineers or materials engineers who wish to enhance their understanding of the fundamental principles of corrosion science. It is assumed that the student or reader does not have a background in electrochemistry. However, the student or reader should have taken at least an undergraduate course in materials science or physical chemistry. More material is presented in the textbook than can be covered in a one-semester course, so the book is intended for both the classroom and as a source book for further use. This book grew out of classroom lectures which the author presented between 1982 and the present while a professorial lecturer at George Washington University, Washington, DC, where he organized and taught a graduate course on “Environmental Effects on Materials.” Additional material has been provided by over 30 years of experience in corrosion research, largely at the Naval Research Laboratory, Washington, DC and also at the Bethlehem Steel Company, Bethlehem, PA and as a Robert A. Welch Postdoctoral Fellow at the University of Texas. The text emphasizes basic principles of corrosion science which underpin extensions to practice.
Download or read book Hydrogen and Fuel Cells written by International Energy Agency and published by Simon and Schuster. This book was released on 2004 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen and fuel cells are vital technologies to ensure a secure and CO2-free energy future. Their development will take decades of extensive public and private effort to achieve technology breakthroughs and commercial maturity. Government research programs are indispensable for catalyzing the development process. This report maps the IEA countries' current efforts to research, develop and deploy the interlocking elements that constitute a "hydrogen economy", including CO2 capture and storage when hydrogen is produced out of fossil fuels. It provides an overview of what is being done, and by whom, covering an extensive complexity of national government R & D programs. The survey highlights the potential for exploiting the benefits of the international cooperation. This book draws primarily upon information contributed by IEA governments. In virtually all the IEA countries, important R & D and policy efforts on hydrogen and fuel cells are in place and expanding. Some are fully-integrated, government-funded programs, some are a key element in an overall strategy spread among multiple public and private efforts. The large amount of information provided in this publication reflects the vast array of technologies and logistics required to build the "hydrogen economy."--Publisher description.
Download or read book Hydrogen Production Technologies written by Mehmet Sankir and published by John Wiley & Sons. This book was released on 2017-03-20 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a comprehensive practical review of the new technologies used to obtain hydrogen more efficiently via catalytic, electrochemical, bio- and photohydrogen production. Hydrogen has been gaining more attention in both transportation and stationary power applications. Fuel cell-powered cars are on the roads and the automotive industry is demanding feasible and efficient technologies to produce hydrogen. The principles and methods described herein lead to reasonable mitigation of the great majority of problems associated with hydrogen production technologies. The chapters in this book are written by distinguished authors who have extensive experience in their fields, and readers will have a chance to compare the fundamental production techniques and learn about the pros and cons of these technologies. The book is organized into three parts. Part I shows the catalytic and electrochemical principles involved in hydrogen production technologies. Part II addresses hydrogen production from electrochemically active bacteria (EAB) by decomposing organic compound into hydrogen in microbial electrolysis cells (MECs). The final part of the book is concerned with photohydrogen generation. Recent developments in the area of semiconductor-based nanomaterials, specifically semiconductor oxides, nitrides and metal free semiconductor-based nanomaterials for photocatalytic hydrogen production are extensively discussed.
Download or read book Thermal Spray Fundamentals written by Pierre L. Fauchais and published by Springer Science & Business Media. This book was released on 2014-01-24 with total page 1587 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with the fundamentals necessary for understanding thermal spray technology. Coverage includes in-depth discussions of various thermal spray processes, feedstock materials, particle-jet interactions, and associated yet very critical topics: diagnostics, current and emerging applications, surface science, and pre and post-treatment. This book will serve as an invaluable resource as a textbook for graduate courses in the field and as an exhaustive reference for professionals involved in thermal spray technology.
Download or read book PEM Fuel Cells written by Frano Barbir and published by Academic Press. This book was released on 2012-09-25 with total page 537 pages. Available in PDF, EPUB and Kindle. Book excerpt: Demand for fuel cell technology is growing rapidly. Fuel cells are being commercialized to provide power to buildings like hospitals and schools, to replace batteries in portable electronic devices, and as replacements for internal combustion engines in vehicles. PEM (Proton Exchange Membrane) fuel cells are lighter, smaller, and more efficient than other types of fuel cell. As a result, over 80% of fuel cells being produced today are PEM cells. This new edition of Dr. Barbir's groundbreaking book still lays the groundwork for engineers, technicians and students better than any other resource, covering fundamentals of design, electrochemistry, heat and mass transport, as well as providing the context of system design and applications. Yet it now also provides invaluable information on the latest advances in modeling, diagnostics, materials, and components, along with an updated chapter on the evolving applications areas wherein PEM cells are being deployed. Comprehensive guide covers all aspects of PEM fuel cells, from theory and fundamentals to practical applications Provides solutions to heat and water management problems engineers must face when designing and implementing PEM fuel cells in systems Hundreds of original illustrations, real-life engineering examples, and end-of-chapter problems help clarify, contextualize, and aid understanding
Download or read book Polymer Electrolyte Fuel Cell Durability written by Felix N. Büchi and published by Springer Science & Business Media. This book was released on 2009-02-08 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers a significant number of R&D projects, performed mostly after 2000, devoted to the understanding and prevention of performance degradation processes in polymer electrolyte fuel cells (PEFCs). The extent and severity of performance degradation processes in PEFCs were recognized rather gradually. Indeed, the recognition overlapped with a significant number of industrial dem- strations of fuel cell powered vehicles, which would suggest a degree of technology maturity beyond the resaolution of fundamental failure mechanisms. An intriguing question, therefore, is why has there been this apparent delay in addressing fun- mental performance stability requirements. The apparent answer is that testing of the power system under fully realistic operation conditions was one prerequisite for revealing the nature and extent of some key modes of PEFC stack failure. Such modes of failure were not exposed to a similar degree, or not at all, in earlier tests of PEFC stacks which were not performed under fully relevant conditions, parti- larly such tests which did not include multiple on–off and/or high power–low power cycles typical for transportation and mobile power applications of PEFCs. Long-term testing of PEFCs reported in the early 1990s by both Los Alamos National Laboratory and Ballard Power was performed under conditions of c- stant cell voltage, typically near the maximum power point of the PEFC.
