Methanol-Enhanced Low-Cell-Voltage Hydrogen Generation at Industrial-Grade Current Density by Triadic Active Sites of Pt1–Pdn–(Ni,Co)(OH)x

Methanol (ME) is a liquid hydrogen carrier, ideal for on-site-on-demand H2 generation, avoiding its costly and risky distribution issues, but this "ME-to-H2" electric conversion suffers from high voltage (energy consumption) and competitive oxygen evolution reaction. Herein, we demonstrate that a synergistic cofunctional Pt1Pdn/(Ni,Co)(OH)x catalyst with Pt single atoms (Pt1) and Pd nanoclusters (Pdn) anchored on OH-vacancy(VOH)-rich (Ni,Co)(OH)x nanoparticles create synergistic triadic active sites, allowing for methanol-enhanced low-voltage H2 generation. For MOR, OH* is preferentially adsorbed on Pdn and then interacts with the intermediates (such as *CHO or *CHOOH) adsorbed favorably on neighboring Pt1 with the assistance of hydrogen bonding from the surface hydrogen of (Ni,Co)(OH)x. The enhanced selectivity of the *CHOOH pathway, instead of *CO, sustains the MOR activity to a practically high current density. For HER, triadic Pt1, Pdn, and OH-vacancy sites on (Ni,Co)(OH)x create an "acid-base" microenvironment to facilitate water adsorption and splitting, forming H* species on Pt1 and Pdn, and *OH at the vacancy, to promote efficient H2 evolution from the asymmetric Pt1 and Pdn sites via the Tafel mechanism. The triadic-site synergy opens new avenues for the design and synthesis of highly efficient and stable cofunctional catalysts for "on-site-on-demand" H2 production, here facilitated by liquid methanol.