Galvanic Displacement-Derived CuOx-Pt/Cu for Operando-Activation and Enhanced HER in Acid

Abstract

This work presents an interesting and easy galvanic displacement strategy for the synthesis of self-supported Pt–Cu heterointerfaces optimized for the hydrogen evolution reaction (HER) in acidic media. By galvanically replacing surface copper with Pt2+ ions, we achieve a unique CuOx-Pt/Cu interface, which undergoes dynamic in-situ activation during HER to form a Pt–Cu2O/Cu heterostructure, in which, Pt is in trace amounts. This transformation significantly enhanced the electrocatalytic HER requiring just 38 mV and 76 mV as overpotentials for 10 and 100 mA cm-2, respectively, outperforming the bulk Pt foil. The synergistic interplay between Pt, Cu2O, and Cu is believed to have delivered a superior charge transfer and active site stabilization, while the self-supporting architecture improves catalyst durability and accessibility. Our approach demonstrates scalable, cost-efficient catalyst fabrication that maximizes Pt utilization while being conservative on the same, providing a promising pathway toward next-generation HER electrocatalysts for efficient green hydrogen production in acidic conditions with ultralow Pt content.