Nano-MgO supported CrOx catalysts applied in propane oxidative dehydrogenation: Relationship between active chromium phases and propane reaction pathway

Propane oxidative dehydrogenation was investigated on nano-MgO supported Cr catalysts. Cr-5.0   wt.% sample exhibited the best catalytic performance with a propylene selectivity of 84.1% and propane conversion of 10.8% at 450   °C. Cr 5 O 12 and MgCrO 4 were proved to be formed, and they could be consecutively reduced as shown by temperature programmed reduction results. The impacts of different Cr phases on propane reaction pathway were also investigated. Fourier transform infrared spectroscopy reflects that Cr 5 O 12 is favorable for the propane dehydrogenation process, while MgCrO 4 would activate propane but lead to the CO x outcome.