Enhancement of light olefin production in CO2 hydrogenation over In2O3-based oxide and SAPO-34 composite

Indium-based oxides are potential catalysts for CO2 hydrogenation to methanol. However, upon complex-ing with SAPO-34, they give a C-2(=)-C-4(=) yield below 7.3% due to production of large amounts of CO and CH4 at high CO2 conversion. Therefore, a large improvement of the C-2(=)-C-4(=) yield over indium-based oxide and zeolite composites is a challenge. In this context, InCeOx and InCrOx oxides were prepared and found to produce more methanol than In2O3 or In-Zr oxide. Experimental and DFT calculation results reveal that incorporation of Ce or Cr into In2O3 generates more surface oxygen vacancies and enhances the electronic interaction between HCOO* intermediates and the catalyst surface, which decreases HCOO* and CH3OH formation free energy barriers and enthalpy barriers. Compared with InCeOx(0.13) and In2O3, InCrOx(0.13) shows higher catalytic activity for CO2 hydrogenation, and by coupling with SAPO-34, it gives a C-2(=)-C-4(=) yield of 1.5-2.0 times those obtained on In2O3/SAPO-34 and In-Zr/SAPO-34 at CO2 conversion of 33.6%. (c) 2020 Elsevier Inc. All rights reserved.