Cerium contained advanced materials: Shining star under electrocatalysis

Cerium (Ce)-based materials are favored in electrocatalytic energy storage and conversion as the most representative member of the rare earth (RE) group. Ce has variable valence and high oxygen storage/release capacity based on abundant oxygen vacancies (O_V), which largely enhances the redox properties of catalysts. It cannot be ignored that the unique 4f electronic structure of the Ce allows it to operate as an electronic modulator to provide additional rhythm for adjusting the functional properties of the catalyst. Recently, emerging novel Ce-based electrocatalytic materials together with continuous progress in advanced characterization techniques (e.g., in situ spectroscopy) and theoretical computational studies continue to enhance our intrinsic knowledge of the electronic and structural effects of Ce and expand the application boundaries. This review presents the inherent fundamental theoretical advantages of Ce in electrocatalysis and further provides a comprehensive summary and constructive discussion of the important research advances in Ce-based electrocatalytic materials in the last five years. Finally, perspectives on the future outlook toward Ce-based advanced electrocatalysts are advocated.