Cu-In intermetallic compounds as highly active catalysts for CH3OH formation from CO2 hydrogenation

Converting CO2 into methanol, utilizing a reproducible hydrogen energy source, is one of the most prospective ways in solving the greenhouse effect and energy shortage. The main challenge is to develop highly efficient catalysts capable of achieving high catalytic activity and stability. Herein, we prepare bimetallic catalysts that can effectively catalytic methanol formation from CO2 hydrogenation with better performance compared to monometallic catalysts, which gives a selectivity close to 90% to methanol. The phase of Cu-In intermetallic catalysts changes significantly with the Cu:In molar ratio, but only two Cu11In9 and Cu7In3 intermetallic compounds emerge. The Cu-In intermetallic compounds and oxygen vacancies existed on In2O3 surface are the two active sites with different roles, and their synergistic catalysis results in the adsorption, activation, and further conversion of CO2 and H-2. When the Cu:In molar ratio equals 1:2, a Cu11In9-In2O3 intermetallic catalyst is obtained by CuO-In2O3 reduction. Moreover, this catalyst possesses the highest Cu specific surface area (the highest Cu dispersion), the highest surface oxygen vacancy concentration (the highest CO2 adsorption capacity), and the optimal synergistic effect between Cu-In intermetallic compound and In2O3. It, therefore, displays the maximum catalytic performance. 10.3% CO2 conversion, 86.2% CH3OH selectivity, and 5.95 mmolCH3OH/h/g CH3OH space-time yield are obtained at 260 degrees C, 3.0 MPa, and 7500 mL/g(cat)/h. CuIn(1:2) owns a good potential as a catalyst for CH3OH synthesis. Novelty Statement Controlled synthesis and catalytic properties of Cu-In intermetallic catalysts. Cu-In intermetallic compounds and In2O3 are the two different active sites. The optimal synergistic effect between Cu11In9 and In2O3 exists in Cu:In(1:2), and Cu:In(1:2) owns an extremely large potential as a catalyst for CH3OH formation from CO2 hydrogenation.