The effect of ZrO2 crystallinity in CrZrOx/SiO2 on non-oxidative propane dehydrogenation

A series of SiO2-supported CrZrOx-based catalysts with same Cr content but different degrees of ZrO2 crystallinity were synthesized by a simple impregnation-calcination method. The catalysts were studied for their activity, selectivity and on-stream stability in non-oxidative propane dehydrogenation (PDH) under industrially relevant conditions. They were characterized by complementary techniques such as XRD, BET, NH3-TPD, H-2-TPR, operando UV-vis, EPR, Raman spectroscopy and TPO. The results demonstrate that ZrO2 crystallinity plays an important role in propene formation. Although catalyst activity can be significantly augmented upon increasing the degree of crystallinity of ZrO2, no decrease in the selectivity could be observed at the same degree of propane conversion, i.e. 92 % at about 20 % conversion. The catalysts showed good durability in 10 PDH/oxidative regeneration cycles at 550 degrees C.