Chromium oxide supported on ZSM-5 as a novel efficient catalyst for dehydrogenation of propane with CO2

ZSM-5-supported chromium oxide catalysts prepared by an incipient wetness method have been tested for the dehydrogenation of propane to propylene in the presence of carbon dioxide. Several techniques including XRD, N2 adsorption, SEM, 27Al MAS NMR, XPS, Raman spectroscopy, diffuse reflectance UV–Vis spectroscopy and H2-TPR were applied to characterize the physicochemical properties of the as-synthesized materials. Catalytic tests show that the chromia catalyst supported on Na-type ZSM-5 with smaller crystal size (ca. 400 nm) exhibits a good catalytic performance, which is much more active than that supported on ZSM-5 with larger crystal size (ca. 2 μm). A high number of Cr(VI) species in the calcined catalyst is crucial for its high catalytic activity in the dehydrogenation of propane to propylene with CO2.

The chromia catalyst supported on Na-type ZSM-5 with smaller crystal size (ca. 400 nm) exhibits much higher catalytic activity than that supported on ZSM-5 with larger crystal size (ca. 2 m) in the dehydrogenation of propane to propylene with CO2 as oxidant.Figure optionsDownload as PowerPoint slideHighlights
► Chromium oxide supported on Na-type ZSM-5.
► The crystal size of ZSM-5 has a significant influence on the catalytic activity.
► Coke formation and reduction of Cr(VI) to Cr(III) are responsible for the catalyst deactivation.
► A high number of Cr(VI) species is crucial for the high catalytic activity.