Phase Interface Engineering of Cu ₁ Co Single Atom Alloy Catalysts for Enhanced Hydrogen Production from Methanol Decomposition

On-site hydrogen production from methanol decomposition has attracted interest in an energy-sustainable society, which compensates for the shortcomings of unsafe hydrogen storage and inconvenient transportation. Here, we constructed Cu 1 Co single atom alloy (SAA) catalysts containing atomically dispersed Cu sites coupled with Co sites serving as intrinsic Cu–Co active sites for hydrogen production from methanol decomposition. It was demonstrated that the reduction temperatures of CuCo precursors induced the generation of distinct crystalline structures and mixed-phase interfaces of Cu 1 Co SAA catalysts, thereby efficiently modulating the electronic structures of the active centers and the surface adsorption and desorption behaviors of the reactants during methanol decomposition. The as-fabricated Cu 1 Co SAA catalyst featuring both the dominant hcp metallic Co phase and abundant hcp/fcc mixed-phase interfaces significantly facilitated a series of dehydrogenation processes of methanol and reaction intermediates and desorption of CO and H 2 products and achieved excellent catalytic performance, with an unprecedentedly high hydrogen production rate of 659.8 mol·mol Cu –1 ·h –1 at complete methanol conversion. By combining structural characterization, in situ spectroscopic analysis, and density functional theory calculations, it was unveiled that atomically dispersed Cu–Co active sites both in the absolutely predominant hcp phase and at the hcp/fcc mixed-phase interfaces on Cu 1 Co SAA catalysts played crucial roles in boosting hydrogen production from methanol decomposition. The present study provides a promising single atomic Cu site-mediated crystal phase and phase interface engineering strategy for developing high-performance and economical Co-based catalysts for methanol decomposition to produce hydrogen.