Oxidative Dehydrogenation of Ethane with CO2 over Novel Cr/SBA-15/Al2O3/FeCrAl Monolithic Catalysts

Abstract

The oxidative dehydrogenation (ODH) of ethane with CO2 was successfully carried out over the Cr-based monolithic catalysts, which were prepared using FeCrAl alloy foil as support. High catalytic activity and stability can be drawn on these monolithic catalysts. For example, 66.5% ethane conversion and 99.5% ethylene selectivity can be achieved on the 5.0% Cr loading monolithic catalyst at 750 °C. After 1130 h of stability reaction, the hexagonal mesoporous structure of SBA-15 was still present and the pore walls of SBA-15 prevented the aggregation of Cr species. It was proposed that the Cr6+ species were responsible for the high catalytic activity of monolithic catalysts. During the reaction, the reduction−oxidation cycle between Cr6+ and Cr3+ species can be carried out via the dehydrogenation of ethane and oxidation by CO2 processes. Interactions between Cr, SBA-15, and the Al2O3/FeCrAl support modify the redox properties of the Cr/SBA-15/Al2O3/FeCrAl catalysts.