Density functional theoretical study of the tungsten-doped In2O3 catalyst for CO2 hydrogenation to methanol

Indium oxide is a promising catalyst for CO2 hydrogenation to methanol and has been extensively investigated in recent years. However, the studies on doped In2O3 for methanol synthesis are relatively few, and tungsten-doped In2O3 has not been reported yet. Herein, the mechanism of the methanol synthesis from CO2 hydrogenation on the defective W-doped In2O3 model (W-In2O3_D) has been investigated via density functional theory (DFT) calculations. The oxygen vacancy on the In2O3 catalyst is essential for the activation and conversion of CO2. The introduction of tungsten results in higher electron density and electron localization on the oxygen vacancy, thus facilitating the activation of CO2. The methanol synthesis on the W-In2O3_D model takes the formate route via the H3CO intermediate. Compared with the In2O3_D model, the cleavage of the C-O bond, the removal of H2O*, and the conversion of HCOO* are promoted by the addition of W. Based on the energetic span model, the turnover frequency (TOF) for the methanol synthesis from CO2 hydrogenation on the W-In2O3_D model is predicted as 9.0 x 10(-3) s(-1), which is much higher than the TOF of 4.5 x 10(-6) s(-1) on the In2O3_D model. Overall, the introduction of tungsten makes the CO2 hydrogenation to methanol kinetically more favorable.

Automated summary

The mechanism of methanol synthesis from CO2 hydrogenation on tungsten-doped In2O3 catalyst was investigated using DFT calculations. The introduction of tungsten increased electron density on oxygen vacancy, facilitating CO2 activation and promoting methanol synthesis. This study suggests that tungsten doping makes CO2 hydrogenation to methanol more efficient.