Research advances and mechanisms of rare earth-based electrocatalysts for water electrolysis

In the context of "dual carbon" goals, the continuous increase in the proportion of green hydrogen is of great significance for the sustainable development of both the environment and the economy. The efficiency of electrocatalysis is contingent on the utilization of high-performance catalysts. In recent years, rare earth elements have demonstrated high application potential in the electrolytic water hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In light of the rapid advancements being made in this research domain, the present review offers a comprehensive overview of the current state of the art concerning the utilization of rare earth element-doped and rare earth element-compound composite catalysts in the context of water electrolysis. Rare earth elements have been shown to enhance the activity and stability of catalysts in the HER and the OER. This enhancement is primarily due to alterations to the electronic structure of the catalysts, the creation of lattice defects (which increases the oxygen vacancy concentration), the modulation of catalyst surface properties, and the regulation of charge transfer rates. Despite the evident potential of rare earth elements in enhancing catalyst performance, the current research is constrained by limitations, particularly in relation to in-depth studies on their application potential under varying pH conditions, long-term stability, cost-effectiveness, and environmental impact. Future research endeavors must delve deeper into the mechanism of rare earth elements in HER and OER catalysts. Furthermore, there is a need to refine the preparation processes to bridge the commercial application gap between them and noble metal catalytic materials. Additionally, there is an opportunity to expand the application scope of electrocatalytic materials. It is anticipated that this review will have a substantial impact on the advancement of rare earth-based electrocatalytic processes.