Rare earth metal-based oxygen electrocatalysts: insights from mechanisms and designs to applications

Abstract

Rare earth metal-based oxygen electrocatalysts show great potential in the field of energy conversion and storage, especially in the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), due to their unique electronic structures and excellent catalytic properties. This paper reviews research progress in rare earth metal-based oxygen electrocatalysts, focusing on synthesis strategies, evaluation indexes, design strategies, and prospects for applications in fuel cells, metal–air batteries, and the electrolysis of water. Firstly, the reaction mechanisms of rare earth metal catalysts in the ORR and OER are analysed, and the intrinsic mechanism of rare earth metals to enhance the reaction rate by regulating the redox behaviour and optimising the surface structure is further revealed with the help of in situ characterisation and other techniques. Secondly, four design strategies for catalysts are introduced, including doping, alloying, compounds, and single atomisation. Finally, the prospects and challenges for the development of rare earth metal-based catalysts are discussed.