Surface Strain Effect on Electrocatalytic Hydrogen Evolution Reaction of Pt-Based Intermetallics
Ziying Zhong, Yuanhua Tu, Longhai Zhang, Jun Ke, Chengzhi Zhong, Weiquan Tan, Liming Wang, Jiaxi Zhang, Huiyu Song, Li Du, Zhiming Cui
Abstract
Elucidating the relationship between electrocatalytic activity and surface strain is pivotal for designing highly efficient electrocatalysts for the acidic hydrogen evolution reaction (HER). However, a general correlation is currently absent due to the lack of ideal catalytic materials platforms with well-defined structures and components. Herein, we select L1 0 and L1 2 Pt-based intermetallic compounds as model materials to construct a series of core–shell catalysts with strained Pt skins (IMC@Pt) and establish the correlation between surface strain and HER performance. Density functional theory calculations were performed to determine the surface strain degree, d-band center, and key descriptor Δ G H* of the catalysts for HER. By combining theoretical and experimental data, we propose a volcano-type trend between surface strain and the HER activity of IMC@Pt with an apex at 4% compressive strain. In addition, we demonstrate a class of highly active and durable IMC@Pt catalysts for acidic HER. Among them, the Pt 3 V@Pt catalyst exhibits the highest intrinsic HER activity with a specific activity of 4.24 mA cm Pt –2 at an overpotential of 20 mV, which is 4 times higher than that of Pt. This work provides a solid understanding of the essential nature of PtM alloy catalysts and can guide the design of high-performance HER catalysts for water electrolyzers.