CO-Induced Reconstruction of Cu-ZnZrOx Catalyst Enables Synergistic CO2/CO Co-Hydrogenation to Methanol.

Catalytically active phase depends strongly on reaction conditions. In CO2 hydrogenation, efforts have largely emphasized CO2 activation while overlooking how to design active phase for the co-conversion of CO2 and the kinetically distinct byproduct CO. Here, it is found that adding CO to CO2-H2 feeds boosts methanol productivity by up to 2.2-fold via a pronounced synergistic promotion of both CO2 and CO hydrogenation over a Cu-ZnZrOx catalyst. In situ spectroscopy reveals that CO accelerates Zn reduction and migration onto Cu, increasing Zn0/Cu ratio, Zn2+/Cu, and Cu+/Cu fraction, while reducing exposed surface Cu from 42% to 19%. This CO-induced restructuring enriches Zn exposure, drives CuZn alloy formation, and creates abundant CuZn alloy-ZnOx interfaces that stabilize Cu+ sites. These interfaces enable a cooperative dual-pathway mechanism: CO2 is hydrogenated mainly via the formate route at alloy-ZnOx sites, whereas CO follows the formyl route on Cu sites. Additionally, in situ-formed water accelerates conversion of the rate-determining CH3O* intermediate in the CO pathway. Together, CO-driven evolution of active sites, synergistic dual-pathway catalysis, and water-assisted promotion yield highly efficient methanol synthesis from mixed CO-CO2 feeds.