Some Aspects of Hydrogen Oxidation in Solid Oxide Fuel Cell: A Brief Historical Overview

Abstract

Environmentally friendly and resource-efficient ways to generate, convert, store and transport electricity are important areas of scientific and technological development. Fuel cells are direct converters of chemical energy into electricity with low emissions of harmful components. One of the most promising types of fuel cells is the solid oxide fuel cell (SOFC). The electrical power generated by the SOFC is mainly limited by the ohmic resistance of the electrolyte and the polarization of the electrodes. The ohmic resistance can be reduced by reducing the thickness of the electrolyte. To reduce the polarization resistance, other approaches are needed, namely a detailed study of the mechanisms of electrode reactions and the determination of the nature of rate-determining stages. Until now, fuel oxidation at the anode of the SOFC, as opposed to oxygen reduction at the cathode, has not been well understood. Even for conventional nickel-ceramic anodes, there is no clear understanding of the nature of the rate-determining steps of hydrogen oxidation. This review provides a brief historical background on the development of SOFCs, some insights into the oxygen reduction mechanisms, and a more detailed review of the kinetics of hydrogen oxidation at SOFC anodes.