Hydrogen Evolution Reaction on Single-Atom Pt Doped in Ni Matrix under Strong Alkaline Condition
Xiurui An, Tingting Yao, Yang Liu, Guifa Long, Aoqi Wang, Zhendong Feng, Michel Dupuis, Can Li
Abstract
Pt catalyst has been considered as the state-of-the-art catalyst for hydrogen evolution reaction (HER) under acid condition. However, its catalytic kinetics under alkaline conditions is not well-understood. Herein, we report a Ni–Pt(SAs) (SAs = single atoms) catalyst with Pt atomically dispersed in a Ni matrix, and it possesses an impressive HER performance with an overpotential as low as 210 mV at 500 mA cm –2 in strong alkaline electrolyte (7 M KOH), which is much higher than Pt nanoparticle-modified Ni catalyst (Ni–Pt(NPs)). Kinetics analysis reveals that Pt doping in the Ni matrix can accelerate the Volmer step on the Ni–Pt surface. Moreover, Ni–Pt(SAs) displays a more favorable kinetics for H 2 formation reaction at high current density than Ni–Pt(NPs). Theoretical calculations reveal that atomically dispersed Pt weakens the adsorption of both H and OH on the surface of Ni–Pt electrode and promotes H 2 formation from surface H on Ni–Pt(SAs).