Tailoring Pt nanoboxes with Bi atoms and SnO2 adatoms for efficient hydrogen evolution electrocatalysis

Engineering Pt-based nanocrystals at the atomic scale holds promise for achieving high-performance electrocatalysts, yet it remains challenging for multimetallic and hierarchical nanostructures. Herein, based on the PtSnBi intermetallic nanoplates with intrinsically isolated Pt, Sn, and Bi atoms, we present the rational design and synthesis of face-centered cubic (fcc) Pt nanoboxes, incorporating dilute Bi atoms within the lattice and SnO2 adatoms on the surface, to enhance acidic hydrogen evolution reaction (HER) electrocatalysis. The prepared SnO2@fcc-Pt0.9Bi0.1 catalyst exhibits ultralow overpotentials of 18.2 and 42.7 mV at 10 and 100 mA cm−2, respectively, accompanied by a favorable Tafel slope of 29.1 mV dec−1. Furthermore, it exhibits high stability, as evidenced by its well-maintained performance at 100 mA cm−2 for 24 h. Experimental characterization combined with density functional theory calculations indicates that hollow geometric engineering, Bi doping, and SnO2 surface modification collectively modulate the electronic structure of the active site and optimize the adsorption strength of hydrogen. Additionally, the engineering of Pt nanoboxes also enhances reaction kinetics, improves intrinsic per-site activity, and expands active surface areas. This work develops a strategy for engineering Pt-based catalysts to improve their HER performance.