Multiple-interface relay catalysis: Enhancing alkaline hydrogen evolution through a combination of Volmer promoter and electrical-behavior regulation

Abstract

Hydrogen evolution reaction (HER) on commercial precious metal catalysts in acid solution is a robust process, but in alkaline media suffers from limitations in HER activity and stability because of the sluggish kinetics of water dissociation step on noble metal catalysts. Here, carbon fiber-supported porous nickel phosphide nanosheets have been used to decorate ruthenium nanoclusters (CF@P-Ni2P/Ru) to generate a hybrid catalyst. The synthesized CF@P-Ni2P/Ru catalyst with multiple- interfaces exhibits overpotential as low as only 45 and 112 mV to deliver current of −10 and −100 mA cmgeo−2, respectively, and long stability of at least 100 h to achieve −10 mA cmgeo−2. Dual-pathway kinetic analysis and density functional theory (DFT) calculations reveal that the hybrids of P-Ni2P and Ru enable stronger water dissociation at the interface of P-Ni2P/Ru and lower the energy barrier of Volmer step, which is beneficial for the HER. Such unique hybrid structure and superior performance provides an important route to fabricating advanced electrocatalysts.