Development of SBA-15 and MCF supported catalysts for selective oxidation reaction of propane to propylene

In this study, V and Ce based mesoporous high surface area catalysts were synthesized. These types of catalysts are known as active catalysts for selective oxidation reactions such as selective oxidation reaction of propane to propylene. Mesoporous SBA-15 and MCF materials, which attracted the attention of researchers in recent years, due to their high surface area, controllable pore structure and thermal stability were used as catalyst supports. Synthesis conditions for SBA-15 were determined basing on the characterization results and reproducable samples were obtained. MCF material was synthesized by using a swelling agent which caused broadening in the pores of SBA-15. V and Ce metals (mixed or alone) were incorporated into SBA-15 and MCF supports by impregnation and direct one-pot synthesis procedures. Characterization studies were carried out to determine physical and structural properties of catalysts. XRD patterns of SBA-15 and MCF showed three peaks which characterized hexagonal structure of materials. Their BET surface areas were found as 924 m2/g and 932 m2/g, for SBA-15 and MCF, respectively. Pore diameter and pore wall thickness of SBA-15 material and cell and window sizes of MCF material were determined by nitrogen adsorption analysis. XRD patterns of V and Ce incorporated SBA-15 catalysts synthesized by the impregnation procedure showed the characteristic three peaks of SBA-15 structure. However, characteristic peaks were not observed in the XRD patterns of V and Ce incorporated SBA-15 catalysts prepared by direct one-pot synthesis procedure. CeVO4 peak was observed in the XRD pattern of V -Ce impregnated mixed metal oxide SBA-15 samples. No change in the surface area of SBA-15 and MCF was observed when one-pot direct synthesis procedure was used for incorporation of V and Ce into the support. But, a decrease in surface area was observed when impregnation technique was used both for SBA-15 and MCF. Pore sizes of the original SBA-15 and MCF were not effected much when V and Ce were incorporated by direct synthesis route, while a decrease in the pore sizes was observed when impregnation technique was used.