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

Abstract 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 Pt 1 @Co 1 CN is fabricated, in which the electronic structure of single Pt sites is modulated by isolated Co atoms pre‐anchored on nitrogen‐doped carbon. Pt 1 @Co 1 CN exhibits superior HOR activity and durability under pH‐universal media than Pt 1 @CN (anchored single Pt atoms on nitrogen‐doped carbon) and commercial PtRu/C and Pt/C. More importantly, Pt 1 @Co 1 CN possesses much better CO anti‐poisoning ability than Pt 1 @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.