The oxygen evolution reaction: Mechanistic concepts and catalyst design

Abstract

Fundamental aspects of the oxygen evolution reaction mediated by metal oxide catalysts are presented. The oxygen evolution reaction is a critical bottleneck in the generation of hydrogen as a renewable fuel via water-splitting. Accordingly, understanding and optimising the oxygen evolution reaction is a major challenge for renewable energy research. In this chapter, key mechanistic concepts are discussed from the perspective of traditional electrochemical kinetics and modern computational methods. The application of a suite of electrochemical techniques forms the basis of a valuable kinetic and mechanistic study of the oxygen evolution reaction and theoretical calculations provide a thermodynamic basis for understanding the electrochemical activity of oxide materials. Building on this fundamental knowledge, oxygen evolution catalyst design is considered in terms of single-parameter activity descriptors and more sophisticated strategies for catalytic enhancement. Taken together, these approaches provide important insight into the requirements for efficient oxygen evolution catalysis. Ultimately, knowledge of the structural and chemical features of the active site is essential for oxygen evolution catalyst design. This chapter concludes with a molecular level consideration of the nature of the active site at metal oxide catalysts, presenting a possible unifying concept in oxygen evolution catalysis which seeks to bridge the field of heterogeneous electrocatalysis with homogeneous molecular catalysis, and relate more general ideas in catalysis to electrochemical studies.