Phosphate Anion as Dynamic Proton Modulator for Efficient Hydrogen Evolution in Alkaline Media

Abstract Achieving a rapid and dynamic balance between proton supply and consumption is crucial for optimizing the kinetics of the hydrogen evolution reaction (HER) and ensuring robust stability under alkaline conditions. Herein, a novel strategy based on bimetal‐site co‐stabilized oxyanions (PO 4 3− ) is proposed that serves as a dynamic proton regulator to enhance alkaline HER performance. This approach enables efficient proton generation to accelerate H 2 ‐evolving kinetics while preventing site blockage and dissolution caused by excessively high local acidity. The Ru and Ni bimetal sites synergistically enhance the adsorption strength of PO 4 3− through bridge oxygen coordination and electronic interactions, thereby addressing the instability of oxyanions in alkaline media. The resulting PO 4 ‐(Ru,Ni)P x /PC (PC denotes phosphorus‐doped carbon) exhibits outstanding catalytic activity with a low overpotential of 15 mV at −10 mA cm −2 and demonstrates excellent stability over 1600 h of continuous operation in alkaline electrolyte. In situ spectroscopic studies combined with electrochemical tests reveal that the incorporated PO 4 3− acts as a dynamic proton modulator: it promotes H─OH bond polarization and water dissociation to facilitate proton generation, while temporarily storing excess protons in the form of protonated phosphates and subsequently transfer them to Ru active sites as needed for efficient H 2 release.