Novel Non-Precious Metal Electrocatalysts for Oxygen Electrode Reactions PDF Download

Author: Hui Yang
Publisher: MDPI
ISBN: 303921540X
Category : Science
Languages : en
Pages : 190

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Book Description
Research on alternative energy harvesting technologies, conversion and storage systems with high efficiency, cost-effective and environmentally friendly systems, such as fuel cells, rechargeable metal-air batteries, unitized regenerative cells, and water electrolyzers has been stimulated by the global demand on energy. The conversion between oxygen and water plays a key step in the development of oxygen electrodes: oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), processes activated mostly by precious metals, like platinum. Their scarcity, their prohibitive cost, and declining activity greatly hamper large-scale applications. This issue reports on novel non-precious metal electrocatalysts based on the innovative design in chemical compositions, structure, and morphology, and supports for the oxygen reaction.

Author: Yongjun Feng
Publisher:
ISBN: 9783039215416
Category : Electronic books
Languages : en
Pages : 1

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Book Description
Research on alternative energy harvesting technologies, conversion and storage systems with high efficiency, cost-effective and environmentally friendly systems, such as fuel cells, rechargeable metal-air batteries, unitized regenerative cells, and water electrolyzers has been stimulated by the global demand on energy. The conversion between oxygen and water plays a key step in the development of oxygen electrodes: oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), processes activated mostly by precious metals, like platinum. Their scarcity, their prohibitive cost, and declining activity greatly hamper large-scale applications. This issue reports on novel non-precious metal electrocatalysts based on the innovative design in chemical compositions, structure, and morphology, and supports for the oxygen reaction.

Author: Nicolas Alonso-Vante
Publisher: John Wiley & Sons
ISBN: 1119460093
Category : Technology & Engineering
Languages : en
Pages : 294

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Book Description
This book addresses some essential topics in the science of energy converting devices emphasizing recent aspects of nano-derived materials in the application for the protection of the environment, storage, and energy conversion. The aim, therefore, is to provide the basic background knowledge. The electron transfer process and structure of the electric double layer and the interaction of species with surfaces and the interaction, reinforced by DFT theory for the current and incoming generation of fuel cell scientists to study the interaction of the catalytic centers with their supports. The chief focus of the chapters is on materials based on precious and non-precious centers for the hydrogen electrode, the oxygen electrode, energy storage, and in remediation applications, where the common issue is the rate-determining step in multi-electron charge transfer processes in electrocatalysis. These approaches are used in a large extent in science and technology, so that each chapter demonstrates the connection of electrochemistry, in addition to chemistry, with different areas, namely, surface science, biochemistry, chemical engineering, and chemical physics.

Author: Ji Liang
Publisher:
ISBN:
Category : Carbon
Languages : en
Pages : 446

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Book Description
Fuel cell is a device that can directly convert the chemical energy in fuels into electricity and it has the advantages including high efficiency, high energy density and zero waste emission. However, a current fuel cell requires noble-metal catalysts (in most cased platinum, Pt) to accelerate the electrode reactions. As a result of the high cost of Pt, the commercialization of fuel cell has been severely hindered. Thus, it is exceptionally important to search for an alternative low-cost catalyst, especially on the cathode when the sluggish oxygen reduction reaction (ORR) occurs and much larger amount of Pt is employed, to bring down the over-all price of a fuel cell. With this aim, this Ph.D thesis has demonstrated the design and synthesis of a serial of high -performance Pt-free catalysts based on carbon materials. These researches include: (1) We firstly designed and constructed a series of porous g-C3N4/C composite with different pore size ranging from large mesopores (ca. 12 nm) to large macropores (ca. 400 nm) and studied the structural impact of these hybrid materials on their ORR performance. In this study, we have for the first time revealed that macropores would be more favorable for ORR in such materials rather than the conventionally believed mesopores. (2) Then, we integrated short-range ordered mesopores into the walls of macropores to form a hierarchical pore structure. By incorporating graphene into this system, its electric conductivity can be enhanced. This is the first study to natively grow graphene on porous carbon. It is found that this material shows an excellent ORR performance with synergistically enhanced activities. Tafel analysis confirms that the good performance was brought from its unique structural advantages. (3) To further enhance the catalytic activity of the above materials with ideal hierarchical structures for ORR, we have introduced high active Fe-N species into the system during the fabrication. By delicate tuning of the Fe content, we are able to control the carbon nano-materials on the hierarchical porous carbon to form graphene or carbon nanotube. As a result, the catalyst has obtained a similarity high performance as Pt as a result of the successful combination of the desired merits for ORR on it. (4) Besides the optimization of materials structure, we have also doped graphene with both N and S, and studied the influence of dual dopants on its ORR activity. We found that a significant performance enhancement was achieved by dual-doping. From density function theory calculation, we found the synergistic effect was from the spin and charge densities redistribution brought by dual-doping of S and N, leading to a larger number of ORR active sites. The studies in this thesis have provided a thorough understand of the kinetic and mechanism of the ORR process on the Pt-free catalysts. The research has not only provided materials with optimized structure and high performance for ORR, but also showed an avenue on the materials' design and construction for further study.

Author: Minhua Shao
Publisher: Springer Science & Business Media
ISBN: 1447149114
Category : Technology & Engineering
Languages : en
Pages : 748

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Book Description
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.

Author: Shuai Zhao
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages :

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Book Description
Fuel cells, one of the most widely studied electrochemical energy conversion devices, together with electrolyzers, a promising energy storage system for natural renewable energy and source of purified hydrogen, have attracted significant research attention in recent years as the demand for energy continues to increase with no end to this energy expansion in sight. However, electrochemical reactions occurring at oxygen electrodes such as the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have very slow kinetics, which has limited the industrialization of both fuel cells and electrolyzers because slow kinetics leads directly high reaction overpotentials. Metal oxides have been widely adopted in terms of electrocatalysts for these oxygen reactions, either as as a support to enhance the stability or activity of platinum, or as the direct catalysts for ORR and OER in alkaline media. However, what is not known is how and why metal oxides as support materials can influence the performance of precious metals through their interactions, what the active sites are for different electrochemical reactions and how to control the desired phases by manipulating the synthesis conditions. This study will probe these very important questions. Chapter 1 of this work provides a background into the ORR/OER mechanism, active sites, and catalyst candidates in electrochemical devices. Chapter 2 presents experimental approaches including material synthesis, and both physical and electrochemical characterization. Chapters 3 and 4 of this study investigate doped metal carbides and metal oxides as support materials for platinum and iridium catalysts for the ORR and OER, respectively, in acidic electrolytes. The Chapter 3 is an investigation of tungsten carbide modified with titanium as a potential non-carbon support for platinum during the ORR in acid media. Chapter 4 discusses the relationship between the synthesis parameters of iridium/iridium oxide supported on titanium-doped tungsten oxide and its durability both ex-situ in a three-electrode cell on a rotating disk electrode (RDE) and in-situ in an operating electrolyzer. Chapter 5 discusses a new method to determine the electrochemically active area of iridium oxide, one of the most common anode catalysts in commercial PEM electrolyzers, in-situ through its electrochemical psuedocapacitance. Chapter 6 probes the performance and function of tin-doped indium oxides (ITO) as a support for platinum ORR catalyst in alkaline media. Metal-support interactions were studied mainly through X-ray photoelectron spectroscopy and electrochemical measurements. Chapter 7 focuses on the electrocatalysis of carbon nanotube (CNT)-supported cobalt oxide for both oxygen reduction and evolution reactions in alkaline media. An optimized procedure to produce a highly stable and active bifunctional ORR/OER hybrid catalyst was developed along with an understanding of the impact of metal oxide anchoring sites and synthesis parameters on catalyst durability. This part of the study provides novel perspectives for the design of carbon-based, hybrid materials and insight into the synthesis-property relationships for these and future electrocatalysts. In summary, this work has studied metal oxides as catalysts and support materials for precious metals during aqueous oxygen reactions. Wherever possible, the fundamental cause for their behavior, including enhanced electrocatalytic activity and durability, was probed thoroughly through physical and electrochemical characterization.

Author: Nasser A M Barakat
Publisher: Mdpi AG
ISBN: 9783036545455
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
The successful commercialization of advanced energy devices, including fuel cells and solar cells (e.g., dye-sensitized solar cells) is somewhat dependent on the cost, activity and durability of the electrocatalysts. Nowadays, precious metal electrodes are the most widely used. Accordingly, the manufacturing costs are relatively high, which constrains wide application. Recently, some reports have introduced some promising non-precious electrocatalysts to be exploited in both oxidation and reduction reactions. It was concluded that immobilization of the functional material on a proper support can distinctly improve catalytic activity. Moreover, due to the synergetic effect, metallic alloy nanoparticles show very good electrocatalytic activity in this regard. This Special Issue aims to cover the most recent progress and the advances in the field of the immobilized non-precious electrocatalysts. This includes, but is not limited to, non-precious electrocatalysts for alcohol (methanol, ethanol, etc.) oxidation, oxygen reduction reaction and electrolyte reduction in dye-sensitized solar cells.

Author: Abhijit Ray
Publisher: BoD – Books on Demand
ISBN: 1789848121
Category : Science
Languages : en
Pages : 130

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Book Description
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.

Author: Francisco Javier Rodríguez-Varela
Publisher: Springer
ISBN: 3319990195
Category : Science
Languages : en
Pages : 302

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Book Description
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.

Author:
Publisher: Elsevier
ISBN: 0080538312
Category : Science
Languages : en
Pages : 677

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Book Description
The book is a multi-author survey (in 15 chapters) of the current state of knowledge and recent developments in our understanding of oxide surfaces. The author list includes most of the acknowledged world experts in this field. The material covered includes fundamental theory and experimental studies of the geometrical, vibrational and electronic structure of such surfaces, but with a special emphasis on the chemical properties and associated reactivity. The main focus is on metal oxides but coverage extends from 'simple' rocksalt materials such as MgO through to complex transition metal oxides with different valencies.