Enhancing Electronic Metal-Support Interaction in Cu-ZnO/N-Carbon Catalysts by Generating More Pyridinic Nitrogen Species for Efficient CO2 Hydrogenation to Methanol

Abstract

The catalytic hydrogenation of CO2 to methanol is a pivotal strategy for carbon neutralization. However, the commonly used Cu-based catalysts are often limited by the activity-stability trade-off and the sluggish kinetics of intermediate conversion in this reaction. Herein, we address these challenges by stabilizing Cu-ZnO nanoparticles on nitrogen-doped ordered mesoporous carbon (NOMC). The optimized N-doped catalyst exhibits superior methanol space-time yield (STY) and selectivity, significantly outperforming its pure carbon-supported counterpart. Electronic structure analyses identify pyridinic nitrogen as the critical anchoring site, which induces a strong Electronic Metal-Support Interaction (EMSI) and thereby enhances the electron density at the Cu active centers. In-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and kinetic studies provide molecular-level evidence that this precise electronic modulation significantly lowers the activation barrier for the rate-determining step (RDS), namely the hydrogenation of stable formate (*HCOO) to methoxy (*CH3O) species. This mechanism effectively unlocks the kinetic bottleneck, facilitating facile methanol synthesis while suppressing the competing reverse water-gas shift (RWGS) reaction. This work unravels the molecular origin of the N-doping effect and establishes a generalizable paradigm for designing robust non-oxide-supported catalysts for sustainable C1 chemistry.