Dehydrogenation of propane over In2O3–Al2O3 mixed oxide in the presence of carbon dioxide

Dehydrogenation of propane (PDH) to propylene in the presence of CO2 was performed over binary In2O3–Al2O3 mixed oxides prepared by alcoholic coprecipitation. Synergistic effect of different composition on the catalytic performance has been observed. Characterization by X-ray diffraction and X-ray photoelectron spectroscopy revealed that the combination of the two components can result in significant modification in the surface properties and bulk dispersion of the In2O3 phase, which in turn leads to a higher reducibility of the In–Al–O composite. A correlation between the temperature-programmed reduction data and the PDH activity for In2O3–Al2O3 revealed that the creation of surface metallic indium species during the reaction is crucial for the dehydrogenation performance. The promoting effect of CO2 on the yield of propylene has been attributed to a facilitation of simple dehydrogenation by its coupling with the reverse water gas shift reaction based on the results from temperature-programmed reaction of CO2 with H2.