Water-induced dynamic Zn3(OH)3 complexes for complete CO2 to methanol conversion on CuZn catalysts

Methanol synthesis through CO2 conversion (CO2 + 3H2 → CH3OH + H2O) offers a sustainable pathway for fuel production and chemical feedstock generation. Although Cu/ZnO/Al2O3 (CZA) catalysts are used industrially for methanol synthesis1, the valorization of CO2 is limited by the need to operate at elevated temperatures (500-550 K), and methanol selectivity is poor due to CO formation via the reverse water-gas shift (RWGS) reaction2,3. Here, we report a methanol production with 100% selectivity and a turnover frequency (TOF) of 1.17 molecules site-1 s-1 at 473 K on CuZn alloys by controlling the amount of water in CO2 and H2 mixture. Using scanning probe microscopy (SPM) from ultrahigh vacuum (UHV) to 5 bar pressure conditions and density functional theory (DFT) calculations, we directly visualize the mobile Zn3(OH)3 complexes generated by the synergistic interaction with H2O/H2 mixtures and demonstrated their structural flexibility in response to reaction intermediates. The synergy between Cu and Zn sites at the interface ensures complete CO2 conversion to methanol. Our study demonstrates the critical effect of precisely controlling the reaction environment for stabilizing highly active catalytic sites that would otherwise be thermodynamically unfavorable, offering a new strategy for catalyst design beyond traditional approaches of tuning surfaces and interfaces.