Cu-Co/In2O3 Bimetallic Catalysts for Improved Methanol Synthesis: Synergistic Effect in CO2 Hydrogenation

In this study, Cu-Co/In2O3 bimetallic catalysts were prepared by using a deposition precipitation method. The strong hydrogen dissociation ability of Cu decreased the reduction temperature of CoO to Co, thereby promoting the formation of the Cu-Co alloy. The interaction between Cu and Co led to electron transfer from Cu to Co, which effectively inhibited the formation of the harmful Cu-In alloy and facilitated the generation of oxygen vacancies in In2O3. The presence of abundant oxygen vacancies in Cu-Co/In2O3 increased CO2 adsorption and promoted the conversion of the methanol intermediate HCOO* to CH3O*. The Cu-Co/In2O3 catalyst exhibited 10.2% conversion and 72% methanol selectivity at 300 degrees C and 5 MPa, which was higher than those of the monometallic catalyst Cu/In2O3 and Co/In2O3.