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.

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.

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.

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.

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.

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.

Meeting the need for a text on solutions to conditions which have so far been a drawback for this important and trend-setting technology, this monograph places special emphasis on novel, alternative catalysts of low temperature fuel cells. Comprehensive in its coverage, the text discusses not only the electrochemical, mechanistic, and material scientific background, but also provides extensive chapters on the design and fabrication of electrocatalysts. A valuable resource aimed at multidisciplinary audiences in the fields of academia and industry.

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.

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.

The growth process of nitrogen-doped carbon nano-structures (CNx) was studied using in-situ and ex-situ characterization techniques. It was found that the Co phase was seen to go through different transformations during the pyrolysis process, depending on the growth substrate used. CNx fibers that formed were acid-washed, and the structure of CNx obtained as well as the nitrogen content was significantly different on the two substrates, which led to activity differences seen in RRDE.