Ultrafast H‐Spillover in Intermetallic PtZn Induced by the Local Disorder for Excellent Electrocatalytic Hydrogen Evolution Performance

Abstract Ordered intermetallic Platinum‐Zinc (PtZn) shows potential in hydrogen evolution reaction (HER), but faces a huge challenge in activity enhancement due to the H‐repulsion properties of Zinc (Zn). Here, local disorder in ordered intermetallic PtZn nanoparticles confined in N‐doped porous carbon (I‐PtZn@NPC) via a confinement‐high‐temperature pyrolysis strategy is realized to boost the HER performance. Experiments and calculations demonstrate that the local substitution of Pt atoms for Zn atoms creates an ultra‐short H‐spillover channel (Pt site→Pt‐Zn bridge site →Zn site). Benefiting from such an ultra‐fast H‐migration from Pt site to Zn site, I‐PtZn@NPC exhibits enhanced intrinsic activity with an ultralow overpotential ( η 10 : 2.3 mV, η 100 : 24 mV) than commercial Pt black catalyst. Furthermore, a 25 cm 2 commercial proton exchange membrane (PEM) electrolyzer equipped with I‐PtZn@NPC achieved stable operation at 1.60 V cell for 200 h at a current density of 1 A cm⁻ 2 . This design of local Zn disorder in the ordered intermetallic PtZn sheds new light on the rational development of efficient Zn‐based alloy HER electrocatalysts.