Breaking the H2O dissociation-OH desorption scaling relationship in alkaline hydrogen evolution by oxophilic single atom M1–Run electrocatalysts†

Abstract

The alkaline electrochemical hydrogen evolution reaction (HER) has been a hot topic in energy catalysis and engineering. Theoretically, intensifying OH adsorption on an electrocatalyst is vital for promoting water dissociation and thus supplying sufficient protons to expedite alkaline hydrogen evolution. However, the overbinding of OH largely impedes the recyclability of active centers and even causes catalyst deactivation. Herein, we report that H₂O dissociation and OH desorption present an undesirable scaling relationship, which poses a major stumbling block to attaining maximized alkaline HER performance. However, dispersing highly oxophilic metal centers to single atoms greatly facilitates OH desorption and meanwhile keeps the high oxophilicity-enabled superb water dissociation merit, hence breaking the proportionality limitation. Based on this finding, a remarkable La₁–Ru_n catalyst is rationally synthesized, which operates durably at an ampere-level current density of 1000 mA cm⁻² for over two months with an ultra-low cell voltage of 1.74 V, showing great promise for practical applications.