Highly selective and stable propane dehydrogenation to propene over dispersed VO_x-species under oxygen-free and oxygen-lean conditions

摘要

For the first time, we reported on a highly selective propane dehydrogenation to propene over S1O2-supported dispersed VO_x species under oxygen-free and oxygen-lean conditions. Propene selectivity above 80% was achieved with propane conversions above 45% at 823-843 K. At operation under oxygen-lean conditions, consecutive propene conversion to CO_X was significantly suppressed and propene was formed additionally via the highly selective non-oxidative dehydrogenation route over the same catalyst. Usage of SiO2 supports (MCM-41, SBA-15, SiO2) with no strong acid sites and co-feeding of small O2 amounts lead to very limited coke formation (<2wt. % after 20 h on-stream operation). This results in only slight decrease in time-on-stream performance (ca. 10% of deactivation during 20 h).