Rare earth-modified catalysts for enhanced hydrogen evolution reaction

Exploring advanced electrocatalysts for hydrogen evolution reaction (HER) is vital for yielding green hydrogen, yet it remains challenging because of the sluggish reaction kinetics and poor stability in harsh environments. Rare earth elements (REEs), owing to their unique electronic structure characterized by 4 f orbital electron cloud, have been employed as a promising modulator for tailoring the electronic properties of catalysts to elevate their HER performance. In order to better understand the mechanism behind the REE-based HER electrocatalysts and guide the future design of more advanced HER electrocatalysts, this review summarizes the recent advances in engineering REE-modified catalysts for boosting electrocatalytic HER, putting special emphasis on the working mechanism of REEs modulators, such as facilitating water dissociation, optimizing the adsorption of intermediates, improving electron transport, and stabilizing the active components. Moreover, the review also outlines the challenges and the perspectives of this interesting field. We hope that the review can provide guidance for the future design of more efficient REEs-based HER electrocatalysts.