Oxidehydrogenation of ethylbenzene to styrene over zirconia-based catalysts with carbon dioxide as soft oxidant

초록

The catalytic performance of titania-zirconia composite oxide supported V2O5/TiO2-ZrO2, CeO2/TiO2-ZrO2, and V2O5-CeO2/TiO2-ZrO2 combination catalysts was evaluated for the oxidative dehydrogenation (ODH) of ethylbenzene to (EB) styrene in the vapor phase under normal atmospheric pressure employing CO2 as a soft oxidant. The TiO2-ZrO2 composite oxide synthesized by a coprecipitation method was in X-ray amorphous form and exhibited a high specific surface area. Deposited vanadium and cerium oxides were in a highly dispersed form over the support surface. The dispersed V2O5 strongly interacted with CeO2 on the TiO2-ZrO2 carrier. The TPR and TPD studies revealed that reduction and desorption profiles, respectively, of the V2O5-CeO2/TiO2-ZrO2 sample were the synergetic combination of V2O5/TiO2-ZrO2 and CeO2/TiO2-ZrO2 samples and indicated the significance of vanadia and ceria addition. The TiO2-ZrO2 mixed oxide and its promoted analogues showed good catalytic activity and selectivity for the ODH of EB. The V2O5-CeO2/TiO2-ZrO2 composite oxide catalyst exhibited a high and stable catalytic activity and selectivity for the ODH of EB with CO2 as the oxidant. This is an abstract of a paper presented at the 236th ACS National Meeting (Philadelphia, PA 8/17-21/2008).