Lattice-hydrogen cycling mechanism enables pH-universal hydrogen evolution at ampere-level current densities
Yan Zhang, Biao Feng, Jingyi Tian, Shiqi Zhou, Changkai Zhou, Yiqun Chen, Xiaoli Xia, Xizhang Wang, Lijun Yang, Luming Peng, Qiang Wu, Hongwen Huang, Zheng Hu
Abstract
Abstract Controllable supply of hydrogen intermediate across a wide pH range is crucial for electroreduction reactions, but is hindered by pH-dependent hydrogen species formation on conventional catalysts. We report a lattice-hydrogen cycling mechanism that dissociates hydrogen intermediate availability from electrolyte pH. By integrating proton-blocking Ru with thermally-hydrogenated H x WO 3 , we create a dynamic hydrogen reservoir, enabling efficient hydrogen supply. In-situ Raman spectroscopy, isotopic labeling, and theoretical simulations reveal the lattice hydrogen in H x WO 3 migrates swiftly to Ru active sites via low-energy-barrier pathways, while consumed hydrogen is spontaneously replenished via proton adsorption (acidic) or water dissociation (alkaline/neutral). Consequently, this catalyst achieves a competitive pH-universal performance for hydrogen evolution reaction, with low overpotentials (125 mV acidic, 142 mV alkaline, 219 mV neutral @1 A cm -2 ) alongside 500-hour stability.