Steric-confinement Rh2/MoS2 dual-atom catalyst directionally modulating adsorption configuration of ester group to boost ethanol synthesis

Abstract

Developing a new tactic for directionally regulating a specific functional group of feedstock molecules at the molecular level is highly desired to synthesize high-value products but remains challenging. We design and construct the two-dimensional molybdenum disulfide (2D MoS₂) nanosheets edge-anchored dual Rh atoms (Rh₂/MoS₂ dual-atom catalyst [DAC]) to boost the ethanol yield in dimethyl oxalate (DMO) selective hydrogenation by precisely manipulating the DMO adsorption configuration. Comprehensive experimental and theoretical results reveal that the pocket-like active center of Rh₂ atoms, with a precise metal-metal distance (3.5 Å), realizes the spatially matched bidentate DMO adsorption via two C=O groups (distance of 3.1 Å), which remarkably enhances the DMO activation and drives the production of ethanol via a unilateral activation mechanism. The turnover frequency (TOF) and H₂/DMO molar ratio of Rh₂/MoS₂ DAC are around 19 times higher and 17 times lower, respectively, than those of the best reported catalysts under comparable conditions. Our results offer practical opportunities for updating the industrial syngas-DMO-ethanol route.