PtCo@PtSn Heterojunction with High Stability/Activity for pH-Universal H2 Evolution

Developing highly efficient Pt-based catalysts through interface engineering is significant for hydrogen production by water electrolysis working at pH-universal conditions but still challenging. Herein, a PtCo@PtSn heterojunction with good hydrogen evolution reaction (HER) performance in pH-universal electrolytes is designed and prepared by combining the advantages of a Pt-based bimetallic alloy and heterojunction. Density functional theory simulations illustrate that the surface electronic structure of Pt is optimized by interface engineering to effectively improve the ability of water dissociation and decrease the Pt  H bond strength for obtaining the suitable H* Gibbs free energy (∆ G H* ). It shows low HER overpotentials in 1.0 m KOH (η −10 = 25 mV), 1.0 m phosphate-buffered saline (η −10 = 18 mV), and 0.5 m H 2 SO 4 (η −10 = 21 mV) solutions, respectively, and it can steadily work for 100 000 (100k) cycles by cyclic voltammetry method. Thus, this work provides a novel strategy to design Pt-based hydrogen evolution catalyst with robust catalytic performance.