Deactivation behavior of CrOy/Al2O3-ZrO2 catalysts in the dehydrogenation of propane to propylene by lattice oxygen

A series of thermally deactivated CrOy/Al2O3-ZrO2 catalysts with different Zr/Al molar ratio (denoted as Cr/AZX, X = Zr/Al molar ratio) were prepared for use in the dehydrogenation of propane to propylene by lattice oxygen of the catalysts. It was found that alpha-chromia-alumina phase was formed as a result of catalyst deactivation. The relative distribution of chromium species was different depending on Zr/Al molar ratio of the catalysts. Among the catalysts, Cr/AZ-0.07 catalyst with the lowest amount of a-chromia-alumina and the largest amount of active chromium species (Cr3+) showed the best catalytic activity in the dehydrogenation of propane to propylene.