Mesoporous nickel oxides as effective catalysts for oxidative dehydrogenation of propane to propene

Mesoporous NiO catalysts prepared by a surfactant-assisted route have been investigated in the oxidative dehydrogenation of propane (ODHP) to propene; these catalysts are compared with two other NiO samples prepared by homogeneous precipitation and sol-gel method, respectively. Mesoporous NiO is proven to be an active and selective catalytic material with an optimum propene yield of 13.2% by the 25.8% propane conversion at 450 degrees C. The propene selectivity remains around 50% in the temperature range from 400 to 550 degrees C. XRD, N-2 adsorption, TEM, O-2-TPD, XPS and Raman characterizations have been used to study the intrinsic differences among these NiO catalysts. The results demonstrate that the densities of O- species and cation vacancies are much higher for the meso-NiO than for other samples; this difference is related to their different catalytic performances. Besides this, the efficient molecular transport by diffusion in the mesoporous channels also plays an important role during the ODHP reaction. (C) 2010 Elsevier B.V. All rights reserved.