Single platinum atoms embedded in nanoporous cobalt selenide as electrocatalyst for accelerating hydrogen evolution reaction

Designing efficient electrocatalysts for hydrogen evolution reaction is significant for renewable and sustainable energy conversion. Here, we report single-atom platinum decorated nanoporous Co₀.₈₅Se (Pt/np-Co₀.₈₅Se) as efficient electrocatalysts for hydrogen evolution. The achieved Pt/np-Co₀.₈₅Se shows high catalytic performance with a near-zero onset overpotential, a low Tafel slope of 35 mV dec⁻¹, and a high turnover frequency of 3.93 s⁻¹ at -100 mV in neutral media, outperforming commercial Pt/C catalyst and other reported transition-metal-based compounds. Operando X-ray absorption spectroscopy studies combined with density functional theory calculations indicate that single-atom platinum in Pt/np-Co₀.₈₅Se not only can optimize surface states of Co₀.₈₅Se active centers under realistic working conditions, but also can significantly reduce energy barriers of water dissociation and improve adsorption/desorption behavior of hydrogen, which synergistically promote thermodynamics and kinetics. This work opens up further opportunities for local electronic structures tuning of electrocatalysts to effectively manipulate its catalytic properties by an atomic-level engineering strategy.