Synthesis and Catalytic Performances of Mesoporous CeNiO Catalysts for the Oxidative Dehydrogenation of Propane to Propene

Mesoporous NiO and CeNiO catalysts were prepared by homogeneous precipitation using sodium dodecyl sulfate (SDS) mixed with triblock copolymer P123 as a template and urea as a hydrolysis-controlling agent. The prepared catalysts were evaluated for the oxidative dehydrogenation of propane (ODP) to propene and the structure and properties of the catalysts were characterized by N-2 adsorption-desorption, transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and H-2 temperature-programmed reduction (H-2-TPR). The results showed that between 400 and 450 degrees C, the NiO and CeNiO catalysts exhibited similar catalytic behavior for the ODP reaction but at low temperatures (<400 degrees C) the catalysts doped with Ce had higher catalytic activity. On NiO only a 3.1% propene yield was obtained at 325 degrees C while the yield on 5CeNiO (n(Ce)/n(Ni)=5%) was as high as 12.2% at the same temperature. The results of N-2 adsorption-desorption and TEM indicated that both the prepared NiO and CeNiO catalysts possessed a high surface area and a wormhole-like mesostructure. The H-2-TPR results revealed that part of the oxygen species became more reducible because of the presence of Ce in CeNiO, which may be the main reason for the higher activities of the catalysts.