Dual Regulation via Oxyphilic Dysprosium Doping: Stabilizing Oxide Support and Customizing Catalytic Pathway for Ampere‐Level Alkaline Hydrogen Evolution

Abstract Achieving robust stabilization of oxide supports under cathodic reduction conditions while enabling an efficient Volmer‐Tafel pathway for the hydrogen evolution reaction (HER) is challenging. Herein, we report a Dy‐doped CuO supported Rh catalyst (Rh@Dy‐CuO), leveraging the oxyphilic Dy for dual regulation to enhance CuO stability and optimize the HER catalytic pathway. Dy incorporation strengthens the Cu‐O bond and mitigates electron aggregation at Cu sites, thereby maintaining the oxidized state of CuO during HER and facilitating efficient H 2 O dissociation to generate adsorbed hydrogen (*H). Concurrently, Dy doping suppresses charge accumulation at the Rh‐CuO interface, enabling seamless *H transfer from CuO to Rh sites. This leads to elevated *H coverage on Rh, promoting rapid *H‐*H coupling via an optimized Tafel step for hydrogen production. As a result, the Rh@Dy‐CuO catalyst delivers a mass activity of 648 mA mg Rh −1 at an overpotential of 100 mV, 46 times higher than that of Pt/C. When applied in an anion exchange membrane water electrolyzer, it delivers 1.91 V at 1.0 A cm −2 with 1000‐hour stability. This Dy‐driven dual regulation offers a novel approach to stabilizing oxide supports and tailoring HER pathways, advancing rare earth‐mediated electrocatalyst design.