Methanol-Enhanced Low-Cell-Voltage Hydrogen Generation at Industrial-Grade Current Density by Triadic Active Sites of Pt<sub>1</sub>–Pd<i><sub>n</sub></i>–(Ni,Co)(OH)<sub><i>x</i></sub>
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
Abstract
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.