A Highly Efficient pH-Universal HOR Catalyst with Engineered Electronic Structures of Single Pt Sites by Isolated Co Atoms

Developing a high-efficiency, stable, and CO-toxicant-resistant low-cost hydrogen oxidation reaction (HOR) electrocatalyst is challenging but is vital for practical proton/anion exchange membrane fuel cells. Herein, an efficient pH-universal HOR catalyst Pt₁@Co₁CN is fabricated, in which the electronic structure of single Pt sites is modulated by isolated Co atoms pre-anchored on nitrogen-doped carbon. Pt₁@Co₁CN exhibits superior HOR activity and durability under pH-universal media than Pt₁@CN (anchored single Pt atoms on nitrogen-doped carbon) and commercial PtRu/C and Pt/C. More importantly, Pt₁@Co₁CN possesses much better CO anti-poisoning ability than Pt₁@CN and commercial PtRu/C and Pt/C. It is speculated that the superior pH-universal HOR performance can be attributed to the inter-regulation of adjacent Co and Pt sites, leading to the downshift of anti-bonding state and consequently strengthening the *H adsorption, which promotes the kinetics of HOR.