Liquid-Phase Selective Oxidation of Alcohols over Vanadium Phosphorus Oxide Catalysts Supported on Nanoporous SBA-15

The vanadium phosphorous oxide (VPO) catalysts, supported on Santa Barbara amorphous molecular sieve (SBA-15) with different vanadium loadings, were prepared by the precipitation method in an organic phase. Techniques such as X-ray diffraction, Bruner-Emmett-Teller method, scanning electron micrograph (SEM), and transmission electron micrograph (TEM) were used for characterization of the catalysts. The high surface area, large pore volume, and pore size of SBA-15 provide an excellent dispersion of (VO)(2)P2O7 species on the support surface. Oxidation of various alcohols was studied in the liquid phase over the VPO/SBA-15 catalyst, using tert-butylhydroperoxide as an oxidant. The activities of VPO/SBA-15 samples were considerably higher than that of the bulk VPO catalyst. At 90 degrees C, the obtained activities were 0.567 and 8: 93 g(pro) .g(-1) VPO.h(-1) over the bulk VPO and 15 wt.% VPO/SBA-15 catalysts, respectively. The effects of substrates, oxidants, reaction time, oxidant/alcohol molar ratio, solvents, amount of catalyst, catalyst recycling, and leaching of VPO in the liquid phase were also investigated.