The superior catalytic activity of In2O3 for CO2 hydrogenation to methanol is demonstrated here. The experimental results demonstrate that the reaction temperature and pressure have a significant influence on methanol yield. The conversion of CO2 over In2O3 increases with the increase of reaction temperature and pressure. The yield and formation rate of methanol also increase with the increase of reaction pressure. However, they increase firstly with the increase of reaction temperature but start to decrease when the temperature rises above 330 °C. At 330 °C and 4 MPa, the yield of methanol reaches 2.82%, while the methanol production rate reaches 3.69 mol h-1 kgcat-1, higher than many other reported catalysts, which normally show very low selectivity of methanol at such high temperature. This confirms the previous theoretical study that In2O3 inhibits the reverse water gas shift, a competitive endothermic reaction for methanol synthesis from CO2 hydrogenation. The mechanism for CO2 hydrogenation to methanol over In2O3 catalyst has been discussed.
Bibliographical noteFunding Information:
This work was supported by SINOPEC (with contract No. 413109) and the National Natural Science Foundation of China (with contract No. 91334206).
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