Oxidative dehydrogenation of C3-C4 paraffins in the presence of CO2 over chromium catalysts

The oxidative dehydrogenation (ODH) of C3-C4 paraffins in the presence of CO2 over chromium catalysts was studied. Chromium catalysts for propane and isobutane ODH were prepared by several different methods, i.e., impregnation (SiO2, Al2O3, and zeolites), ion exchange (zeolite), and equilibrium adsorption (silica). Supported chromium catalysts showed good activity and selectivity in the reaction of propane and isobutane ODH in the presence of CO2. The most active, selective and stable was the catalyst contained 5 wt % of Cr supported on silica and prepared by impregnation method. The addition of ≤ 5 vol % of oxygen resulted in a significant increase of catalyst activity and stability at little decrease of catalyst selectivity