Synthesis Of Carbon Supported Pdsn Electrocatalysts In Alkaline Media

Direct alcohol fuel cells (DAFCs) have received much attention from research academia because of their importance as alternative sources of energy. In this study, PdSn8/C, PdSn10 /C PdSn10.3, PdSn10.7/C, PdSn11/C and PdSn14/C (23 wt%) electrocatalysts on Vulcan XC72 carbon powder were prepared by impregnation reduction method and studied for the reaction of methanol and ethanol electrooxidation in an alkaline medium. The samples were characterized by X-ray Diffraction (XRD) and transmission electron microscopy (TEM). The electrochemical characterization was performed using cyclic voltammetry (CV) and chronoamperometry (CA). It is found that for methanol and ethanol electrooxidation, PdSn10.7/C exhibited higher electrochemical performance than the commercial Pd/C. This realized high performance could be attributed to the generation of OH- species by Sn at lower potential.

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.

The use of expensive platinum-based catalysts has been a major obstacle for the widespread use of low temperature fuel cells. As a result, there is significant commercial and scientific interest in replacing platinum-based electrocatalysts with cost-effective alternatives of comparable performance. This thesis explores the process-structure-property relationship of platinum group metal-free (PGM-free), metal-nitrogen-doped carbon (M-N-C) electrocatalysts for oxygen reduction synthesized by a flame spray pyrolysis process called Reactive Spray Deposition Technology (RSDT). Metal-Nitrogen-Carbon (M-N-C) type Platinum Group Metal-free (PGM-free) electrocatalyst, synthesized directly from liquid solution precursors by the partial combustion of organic material in the RSDT flame. Central to this work is the modification of the RSDT for carbon synthesis using liquid aromatic hydrocarbon-based precursors. The direct synthesis of the M-N-C electrocatalysts using an open atmosphere flame spray pyrolysis technique, has not been reported previously and offers a scalable alternative to the energy-intensive, multi-step furnace-based processes that are conventionally used for synthesizing M-N-C catalysts. The physical and chemical characteristics of the synthesized material are examined and the performance of the catalyst with respect to RSDT process parameters such as precursor composition and fuel equivalence ratio are analyzed with an aim of preparing the groundwork for further development of the synthesis process. The baseline Fe-N-C catalyst synthesized by RSDT exhibits activity towards oxygen reduction in alkaline media and shows excellent dynamic stability even after 4000 potential cycles. Based on these results, additional efforts needed to optimize the RSDT process parameters to improve catalyst activity and for mass-producing M-N-C electrodes are also discussed. As a second subject, this thesis also investigates an application of multi-scale correlative characterization in quality control of carbon black for fuel cell and battery applications. A workflow using correlative characterization techniques including X-CT, laser-milling and elemental analysis is described. Potential failure modes are discussed based on the properties of the impurities analyzed and a case is made for the use of correlative characterization for establishing standards of quality control in commercially produced fuel cell and battery components.

This book is a printed edition of the Special Issue "Electrocatalysis in Fuel Cells" that was published in Catalysts

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.

Nanomaterials have recently garnered significant attention and practical importance for heterogeneous electrocatalysis. This book presents recent developments in the design, synthesis, and characterisation of nanostructured electrocatalytic materials, with a focus on applications to energy and wastewater treatment. Electrocatalytic nanomaterials can enhance process efficiency and sustainability, thus providing innovative solutions for a wide array of areas such as sustainable energy production, conversion, and wastewater treatment. Readers will gain insights into the latest breakthroughs in electrocatalysis and the activity of nanomaterials in energy conversion applications, e.g., fuel cells, hydrogen production, water splitting, and electro/photocatalytic water splitting, as well as for wastewater treatment. The book explores the development of advanced electrocatalysts, particularly hybrid materials.

This book provides a review of the latest advances in anion exchange membrane fuel cells. Starting with an introduction to the field, it then examines the chemistry and catalysis involved in this energy technology. It also includes an introduction to the mathematical modelling of these fuel cells before discussing the system design and performance of real-world systems. Anion exchange membrane fuel cells are an emerging energy technology that has the potential to overcome many of the obstacles of proton exchange membrane fuel cells in terms of the cost, stability, and durability of materials. The book is an essential reference resource for professionals, researchers, and policymakers around the globe working in academia, industry, and government.

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.