CHAPTER 14: Catalytic Aspects of Fuel Cells: Overview and Insights into Solid Oxide Fuel Cells

This chapter provides an overview of fuel cell science and engineering with an emphasis on solid oxide fuel cells (SOFCs). Being known for their high efficiency, low emissions and excellent fuel flexibility, SOFCs are considered to be the most widely used fuel cells. According to the principles of SOFCs, they can operate with any combustible fuel that could react with the immigrated oxide ions through the electrolyte layer. However, in practice, the operation of SOFCs with alternative hydrocarbon fuels can lead to a high level of carbon deposition and cell degradation. Ni-based anode cermets are still the most promising anode material used in SOFCs; however, significant modification needs to be done on their microstructure and composition to enhance their coking resistance. So far, several developments and strategies have been suggested in the literature for improving the long-term durability of Ni-based anodes. In this chapter, the merits and drawbacks of the traditional Ni-yttria-stabilized zirconia anode for SOFCs are discussed, and developments for reaching possible solutions to the problems associated with the direct conversion of hydrocarbon fuels in SOFCs are addressed. In addition, this chapter briefly summarizes the working principles and developments regarding anode materials for hydrocarbon-fuelled SOFCs with the aim of delivering helpful guidance for their future design and development.