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

• DOI: 10.1021/jacs.4c12665
• Publication Date: 2025-01-14T04:23:57Z
• Authors: An Pei; Ruikuan Xie; Lihua Zhu; Fengshun Wu; Zinan Huang; Yongyu Pang; Yu-Chung Chang; Guoliang Chai; Chih-Wen Pao; Qingsheng Gao; Congxiao Shang; Guang Li; Jinyu Ye; Huaze Zhu; Zhiqing Yang; Zhengxiao Guo

[Image: see text] Methanol (ME) is a liquid hydrogen carrier, ideal for on-site-on-demand H(2) generation, avoiding its costly and risky distribution issues, but this “ME-to-H(2)” electric conversion suffers from high voltage (energy consumption) and competitive oxygen evolution reaction. Herein, we demonstrate that a synergistic cofunctional Pt(1)Pd(n)/(Ni,Co)(OH)(x) catalyst with Pt single atoms (Pt(1)) and Pd nanoclusters (Pd(n)) anchored on OH-vacancy(V(OH))-rich (Ni,Co)(OH)(x) nanoparticles create synergistic triadic active sites, allowing for methanol-enhanced low-voltage H(2) generation. For MOR, OH* is preferentially adsorbed on Pd(n) and then interacts with the intermediates (such as *CHO or *CHOOH) adsorbed favorably on neighboring Pt(1) 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 Pt(1), Pd(n), and OH-vacancy sites on (Ni,Co)(OH)(x) create an “acid–base” microenvironment to facilitate water adsorption and splitting, forming H* species on Pt(1) and Pd(n), and *OH at the vacancy, to promote efficient H(2) evolution from the asymmetric Pt(1) and Pd(n) 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” H(2) production, here facilitated by liquid methanol.