Chromium oxide supported on MCM-41 as a highly active and selective catalyst for dehydrogenation of propane with CO2

Abstract

Abstract Incipient wetness technique was used for a preparation of MCM-supported chromium oxide materials with a Cr loading ranging from 0.7 to 13.7 wt%. The obtained samples were characterized by XRD, UV–vis-DRS, H 2 -TPR and BET, and tested as catalysts in dehydrogenation of propane with CO 2 . The catalytic reaction was studied in a flow apparatus at 773–923 K. All the tested catalysts exhibited a good catalytic performance in the dehydrogenation of propane with CO 2 . The best results were achieved over the sample containing 6.8 wt% of Cr. In this case, the selectivity to propene was above 80%, while the conversion of propane increased from 21% (at 773 K) to 62% (at 923 K). The promoting effect of CO 2 on the yield of propene was found for all the studied catalysts. This effect was discussed on the basis of temperature-programmed reaction of CO 2 with H 2 as well as H 2 -TPR experiments after regeneration of the reduced catalyst with pure CO 2 . It was suggested that one of reasons of a higher yield of propene observed in the presence of CO 2 compared to that measured in the absence of CO 2 was coupling of the dehydrogenation of propane with the reverse water–gas shift reaction.