Catalysts in the electrodes of polymer exchange membrane fuel cells (PEMFCs) serve a critical function in reactions which can be used to generate electrical energy from chemical fuels. Pt nanoparticles are commonly dispersed on a conductive support and used as electrode materials in these devices because of their exceptional catalytic activity and electrochemical active surface area. The performance and stability of these electrodes strongly depend on the characteristics of the support. Catalysts supported on high surface area carbon black are widely used in low-temperature fuel cells. In PEMFCs, these catalyst materials can be exposed to high potential and low pH values, resulting in irreversible loss of activity that will limit the useful lifetime of the cell, ultimately leading to its failure. Pt is a noble metal which has good intrinsic stability, but carbon is not thermodynamically stable resulting in the corrosion of the catalyst support under these conditions. The design of more resilient platinum catalyst supports to carry out the successful reaction in a fuel cell's catalyst layer is required to extend the lifetime of PEMFCs degradation. In this thesis, two approaches were used to synthesize robust catalyst support materials for fuel cell applications. In the first case, carbon surfaces were functionalised to enhance their interactions with the catalyst and secondly, stable metal oxide was combined with modified carbon substrates, to maximise contacts within the composite electrocatalysts and to prevent carbon corrosion of a single phase carbon support catalyst. TiO2 NPs, were first chemically bonded to the surfaces of Vulcan carbon to help anchor the Pt catalyst nanoparticles through strong metal-support interactions. Validation of a dual phase catalyst support is an important goal of this research. Each material phase offers a unique advantage that can only be recognized by the preparation of a composite electrocatalyst. Pristine Vulcan (PV) was functionalised with glucose hydroxyl functional groups that react with the base titanium metal alkoxide in a sol-gel reaction and then calcined to form a more chemically crystalline surface. This is followed by impregnation reduction process to deposit the nanostructured Pt catalyst. Material characterization data of synthesized materials were used to correlate the effects of support structure and composition on resilient performance. Advantages from the TiO2/C supports toward performance and durability were contrasted against a set of control samples and demonstrated ex situ. The prepared composite catalysts showed substantial enhancements toward oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) as well as improved stability of the Pt-TiO2 heterogeneous interface formed between catalyst and support. The enhanced performance and durability of these composite catalysts is improved by applying the science of materials and interfaces to the synthesis of composite supports, thus serving as an example for further progress and optimization. Irradiation of these composite catalysts with UV-visible light also showed ~ 171 % photo enhanced activity for MOR, which clearly demonstrates a synergistic effect between the photo- and electrocatalysts. The comparison between the prepared catalysts indicates that there is an appropriate ratio of carbon and TiO2 to obtain the best performance of these photoelectroactive materials. These results demonstrate that methanol oxidation is achieved by electro- and photoelectrocatalysis using a simple and affordable method. This procedure can be conveniently exploited to enhance the response of direct methanol fuel cell electrodes.

Boasting chapters written by leading international experts, Nanostructured and Advanced Materials for Fuel Cells provides an overview of the progress that has been made so far in the material and catalyst development for fuel cells. The book covers the most recent developments detailing all aspects of synthesis, characterization, and performance. It offers an overview on the principles, classifications, and types of fuels used in fuel cells, and discusses the critical properties, design, and advances made in various sealing materials. It provides an extensive review on the design, configuration, fabrication, modeling, materials, and stack performance of μ-SOFC technology, and addresses the advancement and challenges in the synthesis, characterization, and fundamental understanding of the catalytic activity of nitrogen-carbon, carbon, and noncarbon-based electro catalysts for PEM fuel cells. The authors explore the atomic layer deposition (ALD) technique, summarize the advancements in the fundamental understanding of the most successful Nafion membranes, and focus on the development of alternative and composite membranes for direct alcohol fuel cells (DAFCs). They also review current challenges and consider future development in the industry. Includes 17 chapters, 262 figures, and close to 2000 references Provides an extensive review of the carbon, nitrogen-carbon, and noncarbon-based electro catalysts for fuel cells Presents an update on the latest materials development in conventional fuel cells and emerging fuel cells This text is a single-source reference on the latest advances in the nano-structured materials and electro catalysts for fuel cells, the most efficient and emerging energy conversion technologies for the twenty-first century. It serves as a valuable resource for students, materials engineers, and researchers interested in fuel cell technology.

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.

This book commemorates the “Nobel Laureate Professor Suzuki Special Symposium” at the International Union of Material Research Society–International Conference on Advanced Materials (IUMRS-ICAM2017), which was held at Kyoto University, Japan, in 2017. The book begins with a foreword by Professor Akira Suzuki. Subsequently, many authors who attended the special symposium describe the latest scientific advances in the field of carbon materials and carbon nanomaterials including polymers, carbon nanocomposites, and graphene. Carbon-based materials have recently been the focus of considerable attention, given their wide range of potential applications. Fittingly, the chapters in this book cover both experimental and theoretical approaches in several categories of carbon-related materials.

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.