CO-Mediated Relay Catalysis Affords Selective CO2 Hydrogenation to Methanol

Abstract

Although technologically promising for producing petrochemicals directly from renewable resources, CO2 hydrogenation to methanol remains a formidable challenge due to the activity-selectivity trade-off. Current industrial copper-based catalysts often generate substantial CO byproducts that limit CO2 utilization efficiency. Herein, we report a highly active and selective Cu/amorphous ZrO2 (Cu/a-ZrO2) catalyst by using a modified solvothermal method, which achieves a space-time methanol productivity of up to ∼1560 gmethanol kgcat–1 h–1 with a high methanol selectivity of ∼76% at 260 °C. The strategic integration of in situ synchrotron-based vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS), multimodal in situ/operando infrared spectroscopies, kinetic isotope experiments, and computational studies collectively demonstrate that the direct dissociation of C–O bond in CO2 generates *CO followed by subsequent hydrogenation to methanol via relay catalysis on adjacent Cu+–ZrOx and Cu0 dual sites, which subsequently promote the initial activation step of CO2 and the subsequent hydrogenation steps of *CO to methanol, respectively. We confirm that methanol synthesis follows a *CO-mediated mechanism on these sites, highlighting the origin of the excellent performance of self-designed Cu/a-ZrO2.