Effect of Support Structure on the Activity of Cr-Containing Catalysts in Propane Dehydrogenation Involving CO2
摘要
A series of chromium oxide catalysts supported on SiO2 with 5 wt % chromium were synthesized and studied. Silica gel was synthesized by a procedure using the cetyltrimethylammonium bromide template and hydrocarbons capable of solubilization in CTMABr micelles, namely, hexane, cyclohexane, and toluene as “extenders.” The resulting series of supports and catalysts were characterized by physicochemical methods: low-temperature adsorption of N2, XRD, SEM–EDX, and UV–Vis diffuse reflectance spectroscopy. The highest catalytic activity in propane dehydrogenation in the presence of CO2 was exhibited by the 5Cr/SiO2–hexane sample, whose surface contains Cr(III) coexisting with Cr(VI). At 750°C propane conversion was 59.8%; propylene selectivity, 56.2%.