Download or read book Understanding the Role of Transition Metals and Metal Oxides on Carbon Structures for Enhancing Electrocatalytic Activity written by Angela Macedo Macedo Andrade and published by . This book was released on 2021 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies presented in this thesis focus on developing non-precious metal electrodes for oxygen reduction reactions (ORR), oxygen evolution reactions (OER), and hydrogen evolution reaction (HER), the core catalysis of fuel cells and electrolyzers. Metal oxides on carbon support are mainly considered as the catalytically active materials in this study. Two approaches of fabrication are presented: one based upon atomic layer deposition (ALD) and one by a wet synthesis process known as the solvothermal method. The resulting catalysts are characterized to reveal the process-performance relationship for ORR, OER, and HER. In the first study (Chapter 4), we demonstrate a bimetallic Co/Cu-embedded N-doped carbon structure for trifunctional catalysis of ORR, OER, and HER in alkaline media. A hybrid catalyst synthesized through a metal-organic framework-based process (M-NC-CoCu) enables active trifunctional catalysis due to its multi-faceted favorable characteristics. It is believed that a range of catalytically active sites are formed through the approach including well-dispersed tiny CuCo2O4 phases, a high concentration of pyridinic and graphitic N, and Cu-Ox, Cu-Nx, and Co-Nx moieties. In addition, a high-surface-area morphology with a high concentration of sp2 bonding, which is beneficial for facilitated electron conduction, further contributes to the performance as an electrocatalyst. The second study (Chapter 5) investigates the catalytic activities of titanium dioxide (TiO2) incorporated onto graphene oxygen (GO) by atomic layer deposition (ALD). The catalytic activity was systematically measured by cyclic voltammetry (CV). Evidence shows that TiO2 bonded on the surface of GO is catalytic active. An ALD treatment of TiO2 shows improvement in the catalytic activity compared to non-treated graphene. The ALD temperature also affects the catalytic performance. A higher temperature results in a higher catalytic activity, which is ascribed to the simultaneous reduction of GO and the addition of catalytically active TiO2/GO interfaces by ALD. In addition, there is also an optimal number of ALD cycles for enhanced catalytic activity. In the third study (Chapter 6), a zinc-based zeolitic imidazole framework (ZIF-8) is carbonized to form organized N-doped carbon nanostructures. The carbonized ZIF-8 (C-ZIF-8) was then used as a substrate (support) for ALD. Titanium (Ti) and/or cerium (Ce) precursors were introduced to the ALD chamber to form bimetallic (Ti and Ce) or monometallic (Ti or Ce) hybrids with C-ZIF-8. I investigated the effects of bimetal incorporation in the electrocatalytic properties of the resulting hybrid systems toward OER and HER. The optimization of ALD parameters, such as the number of cycles, temperature, and pressure for catalytic performance are also discussed.

Download or read book Advanced Electrocatalysts for Low Temperature Fuel Cells written by Francisco Javier Rodríguez-Varela and published by Springer. This book was released on 2018-10-09 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the reader to the state of the art in nanostructured anode and cathode electrocatalysts for low-temperature acid and alkaline fuel cells. It explores the electrocatalysis of anode (oxidation of organic molecules) and cathode (oxygen reduction) reactions. It also offers insights into metal-carbon interactions, correlating them with the catalytic activity of the electrochemical reactions. The book explores the electrocatalytic behaviour of materials based on noble metals and their alloys, as well as metal-metal oxides and metal-free nanostructures. It also discusses the surface and structural modification of carbon supports to enhance the catalytic activity of electrocatalysts for fuel-cell reactions.

Download or read book Understanding the Catalytic Activity of Oxides Through Their Electronic Structure and Surface Chemistry written by Kelsey Ann Stoerzinger and published by . This book was released on 2016 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: The intermittent nature of renewable energy sources requires a clean, scalable means of converting and storing energy. Water electrolysis can sustainably achieve this goal by storing energy in the bonds of oxygen and hydrogen molecules. The efficiency of this storage-conversion process is largely determined by the kinetic overpotential required for the oxygen evolution and reduction reactions (OER and ORR), respectively. This thesis focuses on transition metal oxides as alternative oxygen catalysts to costly and scarce noble metals. In order to develop descriptors to improve catalytic activity, thus reducing material cost for commercial technologies, this work studies fundamental processes that occur on model catalyst systems. Electrochemical studies of epitaxial oxide thin films establish the intrinsic activity of oxide catalysts in a way that cannot be realized with polydisperse nanoparticle systems. This thesis has isolated the activity of the catalyst on a true surface-area basis, enabling an accurate comparison of catalyst chemistries, and also revealed how different terminations and structures affect the kinetics. These studies of epitaxial thin films are among the first to probe phenomena that are not straightforward to isolate in nanoparticles, such as the role of oxide band structure, interfacial charge transfer (the "ligand" effect), strain, and crystallographic orientation. In addition, these well-defined surfaces allow spectroscopic examinations of their chemical speciation in an aqueous environment by using ambient pressure X-ray photoelectron spectroscopy. By quantifying the formation of hydroxyl groups, we compare the relative affinity of different surfaces for this key reaction intermediate in oxygen electrocatalysis. The strength of interaction with hydroxyls correlates inversely with activity, illustrating detrimental effects of strong water interactions at the catalyst surface. This fundamental insight brings molecular understanding to the wetting of oxide surfaces, as well as the role of hydrogen bonding in catalysis. Furthermore, understanding of the mechanisms of oxygen electrocatalysis guides the rational design of high-surface-area oxide catalysts for technical application.

Download or read book Metal Oxides Chalcogenides and Composites written by Aneeya Kumar Samantara and published by Springer. This book was released on 2019-08-09 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the recent development of metal oxides, hydroxides and their carbon composites for electrochemical oxidation of water in the production of hydrogen and oxygen as fuels. It includes a detailed discussion on synthesis methodologies for the metal oxides/hydroxides, structural/morphological characterizations, and the key parameters (Tafel plot, Turnover frequency, Faradic efficiency, overpotential, long cycle life etc.) needed to evaluate the electrocatalytic activity of the materials. Additionally, the mechanism behind the electro oxidation process is presented. Readers will find a comprehensive source on the close correlation between metal oxides, hydroxides, composites, and their properties and importance in the generation of hydrogen and oxygen from water. The depletion of fossil fuels from the earth’s crust, and related environmental issues such as climate change, demand that we search for alternative energy resources to achieve some form of sustainable future. In this regard, much scientific research has been devoted to technologies such as solar cells, wind turbines, fuel cells etc. Among them fuel cells attract much attention because of their versatility and efficiency. In fuel cells, different fuels such as hydrogen, CO2, alcohols, acids, methane, oxygen/air, etc. are used as the fuel, and catalysts are employed to produce a chemical reaction for generating electricity. Hence, it is very important to produce these fuels in an efficient, eco-friendly, and cost effective manner. The electrochemical splitting of water is an environmentally friendly process to produce hydrogen (the greener fuel used in fuel cells), but the efficiencies of these hydrogen evolution reactions (cathodic half reaction) are strongly dependent on the anodic half reaction (oxygen evolution reaction), i.e., the better the anodic half, the better will be the cathodic reaction. Further, this oxygen evolution reaction depends on the types of active electrocatalysts used. Though many more synthetic approaches have been explored and different electrocatalysts developed, oxide and hydroxide-based nanomaterials and composites (with graphene, carbon nanotubes etc.) show better performance. This may be due to the availability of more catalytic surface area and electro active centers to carry out the catalysis process.

Download or read book Electrocatalysts for Fuel Cells and Hydrogen Evolution written by Abhijit Ray and published by BoD – Books on Demand. This book was released on 2018-12-05 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book starts with a theoretical understanding of electrocatalysis in the framework of density functional theory followed by a vivid review of oxygen reduction reactions. A special emphasis has been placed on electrocatalysts for a proton-exchange membrane-based fuel cell where graphene with noble metal dispersion plays a significant role in electron transfer at thermodynamically favourable conditions. The latter part of the book deals with two 2D materials with high economic viability and process ability and MoS2 and WS2 for their prospects in water-splitting from renewable energy.

Download or read book Direct Methanol Fuel Cell Technology written by Kingshuk Dutta and published by Elsevier. This book was released on 2020-02-25 with total page 565 pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct Methanol Fuel Cell Technology presents the overall progress witnessed in the field of DMFC over the past decade, highlighting the components, materials, functions, properties and features, designs and configurations, operations, modelling, applications, pros and cons, social, political and market penetration, economics and future directions. The book discusses every single aspect of DMFC device technology, the associated advantages and drawbacks of state-of-the-art materials and design, market opportunities and commercialization aspects, and possible future directions of research and development. This book, containing critical analyses and opinions from experts around the world, will garner considerable interest among actual users/scientists/experts. Analyzes developments of membrane electrolytes, electrodes, catalysts, catalyst supports, bipolar plates, gas diffusion layers and flow channels as critical components of direct methanol fuel cells Includes modeling of direct methanol fuel cells to understand their scaling up potentials Discusses commercial aspects of direct methanol fuel cells in terms of market penetration, end application, cost, viability, reliability, social and commercial perception, drawbacks and prospects

Download or read book Nanocarbons for Advanced Energy Storage written by Xinliang Feng and published by John Wiley & Sons. This book was released on 2015-08-25 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this second volume in the first book series on nanocarbons for advanced applications the highly renowned series and volume editor has put together a top author team of internationally acclaimed experts on carbon materials. Divided into three major parts, this reference provides a current overview of the design, synthesis, and characterization of nanocarbons, such as carbon nanotubes, fullerenes, graphenes, and porous carbons for energy conversion applications. It covers such varied topics as electrocatalysts for oxygen reduction reactions in the different types of fuel cells, metal-air batteries and electrode materials for photovoltaic devices, as well as photocatalysts, electrocatalysts and photoelectrocatalysts for water splitting. Throughout, the authors highlight the unique aspects of nanocarbon materials in these fields, with a particular focus on the physico-chemical properties which lead to enhanced device performances.

Download or read book Green Energy Harvesting written by Pooja Devi and published by John Wiley & Sons. This book was released on 2022-10-18 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive resource summarizing current approaches to generating hydrogen from water and reducing CO2 into various hydrocarbons Green Energy Harvesting: Materials for Hydrogen Generation and Carbon Dioxide Reduction provides an in-depth treatment of the subject by exploring the fundamentals required for the selection of the materials, their synthesis methods, and possible ways to modify them for higher efficiency and enhanced stability. The prospects of adopting these sustainable solutions at a commercial level are summarized. Special emphasis is given to the figure-of-merits for currently developed systems for hydrogen generation and CO2 reduction and to an assessment of available materials in terms of efficacy and efficiency. Green Energy Harvesting also includes information on: Renewable energy in general, including the role of renewable hydrogen and hydrocarbon fuels, and possible renewable energy sources A fundamental understanding hydrogen generation and CO2 reduction Device development and deployment status for commercial usage and applications of H2 and hydrocarbon fuels in various sectors Electrocatalysts, 2D materials, and hybrid materials for CO2 reduction and H2 generation Green Energy Harvesting is a highly useful guide for both novice and experienced researchers involved in renewable energy and carbon dioxide utilization that explains the current state of the field and discusses future perspectives.

Download or read book Green Chemical Synthesis with Microwaves and Ultrasound written by Dakeshwar Kumar Verma and published by John Wiley & Sons. This book was released on 2024-06-10 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Green Chemical Synthesis with Microwaves and Ultrasound A guide to the efficient and sustainable synthesis of organic compounds Chemical processes and the synthesis of compounds are essential aspects of numerous industries, and particularly central to the creation of drug-like structures. Their often significant environmental biproducts, however, have driven substantial innovations in the areas of green and organic synthesis, which have the potential to drive efficient, solvent-free synthesis and create more sustainable chemical processes. The use of microwaves and ultrasounds in chemical synthesis has proven an especially fruitful area of research, with the potential to produce a more sustainable industrial future. Green Chemical Synthesis with Microwaves and Ultrasound provides a comprehensive overview of recent advances in microwave- and ultrasound-driven synthesis and their cutting-edge applications. Green Chemical Synthesis with Microwaves and Ultrasound readers will also find: Introduction to the key equipment and tools of green chemical synthesis Detailed discussion of methods including ultrasound irradiation, metal-catalyzed reactions, enzymatic reactions, and many more An authorial team with immense experience in environmentally friendly organic chemical production Green Chemical Synthesis with Microwaves and Ultrasound is ideal for chemists, organic chemists, chemical engineers, biochemists, and any researchers or industry professionals working on the synthesis of chemicals and/or organic compounds.

Download or read book Handbook of Porous Carbon Materials written by Andrews Nirmala Grace and published by Springer Nature. This book was released on 2023-03-06 with total page 1176 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook summarizes the current advancements and growth in sustainable carbonaceous porous materials for fabrication and revival of energy devices, fuel cells, sensors technology, solar cell technology, stealth technology in addition to biomedical applications. It also covers the potential applications of carbon materials in various fields such as chemical, engineering, biomedical and environmental sciences. It also confers the prospective utilization of 2D and 3D hierarchical porous carbon in different interdisciplinary engineering applications. The book discusses major challenges faced in the development of cost-effective future energy storage strategies and provides effective solutions for improvement in the performance of carbon-based materials. Given the content, this handbook will be useful for students, researchers and professionals working in the area of material chemistry and allied fields.

Download or read book Electrocatalysis in Fuel Cells written by Minhua Shao and published by Springer Science & Business Media. This book was released on 2013-04-08 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuel cells are one of the most promising clean energy conversion devices that can solve the environmental and energy problems in our society. However, the high platinum loading of fuel cells - and thus their high cost - prevents their commercialization. Non- or low- platinum electrocatalysts are needed to lower the fuel cell cost. Electrocatalysis in Fuel Cells: A Non and Low Platinum Approach is a comprehensive book summarizing recent advances of electrocatalysis in oxygen reduction and alcohol oxidation, with a particular focus on non- and low-Pt electrocatalysts. All twenty four chapters were written by worldwide experts in their fields. The fundamentals and applications of novel electrocatalysts are discussed thoroughly in the book. The book is geared toward researchers in the field, postgraduate students and lecturers, and scientists and engineers at fuel cell and automotive companies. It can even be a reference book for those who are interested in this area.

Download or read book Advanced Technologies for Rechargeable Batteries written by Prasanth Raghavan and published by CRC Press. This book was released on 2024-08-22 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume covers recent advanced battery systems such as metal-ion, hybrid, and metal-air batteries. It includes an introduction to fluoride, potassium, zinc, chloride, aluminium, and iron-ion batteries; special or hybrid batteries are included, with calcium, nuclear, thermal, and lithium-magnesium hybrid batteries also explained. It summarizes the recent progress and chemistry behind the popular metal-air batteries, including a systematic overview of the components, design, and integration of these new battery technologies. Features: Covers recent battery technologies in detail, from the chemistry to advances in post-lithium-ion batteries. Various post-lithium-ion batteries are discussed in detail. Includes a section on ion batteries, exploring new types of metal-ion batteries. Focuses in each chapter on a particular battery type, including different metal-ion batteries such as zinc, potassium, aluminium, and their air version batteries. Provides authoritative coverage of scientific content via global contributing experts. This book is aimed at graduate students, researchers, and professionals in materials science, chemical and electrical engineering, and electrochemistry.

Download or read book Hydrogen Fuel Cell Technology for Stationary Applications written by Badea, Gheorghe and published by IGI Global. This book was released on 2021-04-30 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unconventional energy sources have gained and will continue to gain an increasing share of energy systems around the world. Today, hydrogen is recognized as a non-polluting energy carrier because it does not contribute to global warming if it is produced from renewable sources. Hydrogen is already part of today's chemical industry, but as an energy source, its rare advantages can only be obtained with the help of technologies. Currently, the fuel cell is considered the cleanest sustainable energy. With the development of fuel cells, hydrogen-based energy generation becomes a reality. Hydrogen Fuel Cell Technology for Stationary Applications is an essential publication that focuses on the advantages of hydrogen as a primary energy center and addresses its use in the sustainable future of stationary applications. While highlighting a broad range of topics including cost expectations, production methods, and social impact, this publication explores all aspects of the implementation and dissemination of fuel cell technology in the hope of establishing a sustainable marketplace for it. This book is ideally designed for fuel cell manufacturers, architects, electrical engineers, civil engineers, environmental engineers, advocates, manufacturers, mechanics, researchers, academicians, and students.

Download or read book Strong metal support interaction of Pt based electrocatalysts with transition metal oxides nitrides carbides for oxygen reduction reaction written by Min Chen and published by OAE Publishing Inc.. This book was released on 2023-06-06 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electrospinning for Advanced Energy and Environmental Applications written by Sara Cavaliere and published by CRC Press. This book was released on 2015-09-01 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrospinning for Advanced Energy and Environmental Applications delivers a state-of-the-art overview of the use of electrospun fibers in energy conversion and storage, as well as in environmental sensing and remediation. Featuring contributions from leading experts in electrospinning and its specific applications, this book: Introduces the elect

Download or read book Interplay Between Electronic Structure and Catalytic Activity in Transition Metal Oxide Model System written by Jin Suntivich and published by . This book was released on 2012 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: The efficiency of many energy storage and conversion technologies, such as hydrogen fuel cells, rechargeable metal-air batteries, and hydrogen production from water splitting, is limited by the slow kinetics of the oxygen electrochemical reactions. Transition-metal oxides can exhibit high catalytic activity for oxygen electrochemical reactions, which can be used to improve efficiency and cost of these devices. Identifying a catalyst "design principle" that links material properties to the catalytic activity can accelerate the development of highly active, abundant transition metal oxide catalysts fore more efficient, cost-effective energy storage and conversion system. In this thesis, we demonstrate that the oxygen electrocatalytic activity for perovskite transition metal oxide catalysts primarily correlates to the a* orbital ("eg") occupation. We further find that the extent of B-site transition metal-oxygen covalency can serve as a secondary activity descriptor. We hypothesize that this correlation reflects the critical influences of the a* orbital and transition metal-oxygen covalency on the ability of the surface to displace and stabilize oxygen-species on surface transition metals. We further propose that this ability to stabilize oxygen-species reflect as the rate-limiting steps of the oxygen electrochemical reactions on the perovskite oxide surfaces, and thus highlight the importance of electronic structure in controlling the oxide catalytic activity.

Download or read book Transition Metal Oxides written by P. A. Cox and published by Oxford University Press. This book was released on 2010-08-19 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal oxides form a series of compounds with a uniquely wide range of electronic properties. They have important applications as dielectrics,semiconductors, and metals, and as materials for magnetic and optical uses. The recent discovery of `high temperature' superconductors has brought the attention of a wide scientific community to this area and has highlighted the problems involved in trying to understand transition metal oxides. The present book is not primarily about Tc superconductors, although their main properties are discussed in the final sections. The main aim is to describe the varied electronic behaviour shown by transition metal oxides, and to discuss the different types of theoretical model that have been proposed to interpret it. It is intended to provide an introduction to this fascinating and difficult field, at a level suitable for graduate students and other research workers with a background in solid- state chemistry or physics.