Accelerated alkaline hydrogen evolution on M(OH) _x /M-MoPO _x (M = Ni, Co, Fe, Mn) electrocatalysts by coupling water dissociation and hydrogen ad-desorption steps.

ABSTRACT: Developing efficient and cheap electrocatalysts for the alkaline hydrogen evolution reaction is still a big challenge due to the sluggish water dissociation kinetics as well as poor M-H_ad energetics. Herein, hydroxide modification and element incorporation have been demonstrated to realize a synergistic modulation on a new class of M(OH) _x /M-MoPO _x catalysts for accelerating water dissociation and hydrogen ad-desorption steps in the HER. Theoretical and experimental results disclosed that in situ modification with hydroxide endowed M(OH) _x /M-MoPO _x with a strong ability to dissociate water, and meanwhile, oxygen incorporation effectively optimized the M-H_ad energetics of the NiMoP catalyst. Moreover, the interaction between M(OH) _x and M-MoPO _x components in M(OH) _x /M-MoPO _x further enhances their ability to catalyze the two elementary steps in alkaline hydrogen evolution, providing a wide avenue for efficiently catalyzing hydrogen evolution. In general, the optimized Ni(OH)₂/NiMoPO _x catalyst exhibits excellent alkaline HER activity and durability, superior to the state-of-the-art Pt/C catalyst when the overpotential exceeds 65 mV.

SUBMITTER: Peng L 

PROVIDER: S-EPMC8157449 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature