CuO/ZnO/Al2O3 Catalyst Prepared by Mechanical-Force-Driven Solid-State Ion Exchange and Its Excellent Catalytic Activity under Internal Cooling Condition

CuO/ZnO/Al2O3 catalysts were prepared by a mechanical-force-driven solid-state ion-exchange method, and their catalytic performance for methanol synthesis was investigated in a manufactured reactor with an internal cooling system. With the increasing of milling speed during ball-milling, the ion exchange between Cu2+ and Zn2+ in catalyst precursors is enhanced. After calcination, CuO nanoparticles are neighboring to ZnO nanoparticles and ZnO nanoparticles serve as spacers to prevent the agglomeration of CuO nanoparticles, leading to a cross-distribution of CuO and ZnO in catalysts. The as-prepared catalysts exhibit excellent catalytic activities, and the highest CO2 conversion and CH3OH yield at 240 degrees C and 4 MPa can reach 59.5% and 43.7%, respectively. The extraordinary catalytic performance can be attributed to both the cross-distribution of CuO and ZnO nanoparticles caused by solid-state ion exchange and the promotion of reversible CO2 hydrogenation reaction toward methanol synthesis by the internal cooling system.