LAUSR

Electrocatalysts with high activities towards multiple electrode reactions are scarce and therefore highly sought. Here, we investigate electrocatalytic performance of the two-dimensional (2D) Pt5Se4 monolayer towards hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Our density-functional theory calculations show that the Pt5Se4 monolayer can serve as a low-Pt-loading trifunctional electrocatalyst with good kinetic and thermal stabilities. Specifically, the HER performance of Pt5Se4 basal plane is predicted to be superior to that of 2D layered Pd or Pt dichalcogenides. Even considering the solvent effect, the catalytic OER performance of Pt5Se4 monolayer is predicted to be comparable to the prevalent OER catalyst-IrO2, while the catalytic ORR performance of Pt5Se4 monolayer is even higher than the predominating Pt (111) surface. Overall, the Pt5Se4 monolayer can be a promising trifunctional catalyst that exhibits high activities towards all hydrogen and oxygen electrode reactions.