In situ controllable reconstruction of hydrogen spillover channel towards ampere-level hydrogen evolution in alkaline media

Acceleration of hydrogen spillover on electrocatalysts is effective for improving the hydrogen evolution reaction. However, it is still challenging to design rational proton migration pathway. Herein, we propose an in-situ reconstruction strategy to provide MoO 4 2− -modified micro-environment, which prominently promotes the hydrogen spillover effect. The Mo species is introduced to be in situ oxidized and transformed to MoO 4 2− . Experimental and theoretical studies indicate that the generation and re-adsorption of MoO 4 2− not only suppress the interfacial electron accumulation, but also optimize the electronic structure to facilitate thermo-neutral adsorption of H*, thus forming the effective hydrogen spillover channel. Finally, the reconstructed catalyst exhibits excellent HER performance (overpotential of 183 mV at 1000 mA cm −2 in alkaline solution) and sustained high stability for 1000 h at 1000 mA cm −2 , which also shows great promising prospects for practical applications ( E W : 4.09 kW h m −3 ; η ETH : 86%@60 ℃) in anion exchange membrane alkaline water electrolyzer.