Promoting Cu/ZnOx Interface Formation and Zn-H-Zn Activation in Industrial CuZnAl Catalysts via ZrO2 Doping for Methanol Synthesis

Although industrial Cu/ZnO/Al 2 O 3 catalysts are highly promising for methanol synthesis from CO 2 hydrogenation, identifying the nature of the surface active structure and establishing a quantitative structure-activity relationship remain elusive. Herein, through integrated qualitative, titration, and isothermal adsorption characterizations, we elucidate how Zr species promotion tailors the electronic and structural properties of Cu/ZnO x interfacial sites—the primary active sites. A substantial methanol STY of 0.813 g g cat –1 h –1 is achieved over the Cu/ZnO/Al 2 O 3 -2Zr catalyst at 503 K and 3 MPa with an H 2 /CO 2 ratio of 4 and a GHSV of 40,000 mL g cat –1 h –1 , a 23.9% leap over the pristine benchmark. Mechanistically, a linear dependence of CO 2 conversion on the density of Cu/ZnO x interfacial sites is established, which originates from the improved dispersion of both ZnO and Cu induced by moderate ZrO 2 incorporation. Electronic analyses reveal that Zr species acts as an electron donor to ZnO x , enriching its electron density. This electronic modulation facilitates H 2 dissociation and the surface Zn-H-Zn species formation even at low temperature, selectively driving the intermediate hydrogenation to methanol. In situ spectroscopies identify a sequential HCOO* → CH 3 O* hydrogenation pathway for methanol synthesis. Ultimately, this work establishes a definitive quantitative structure-activity relationship, paving a clear path for designing advanced industrial methanol catalysts.