Well-dispersed Ceria-promoted Sulfated Zirconia Supported on Mesoporous Silica

Abstract

Ceria-promoted sulfated zirconia (CeSZ) was supported on mesoporous molecular sieve of pure-silica MCM-41 (abbreviated as CeSZ/MCM-41). It was prepared by direct impregnation of metal sulfate onto the as-synthesized MCM-41, followed by solid state dispersion and thermal decomposition. The resultant catalysts were characterized by TG, XRD, nitrogen physisorption and TEM. It was showed that the hollow tubular structure of MCM-41 was retained, even with ZrO2 loading as high as 60 wt.%. Most of CeSZ was well dispersed on the interior surface of the ordered mesopores, following a slight twist of the channels. The catalytic activity of CeSZ/MCM-41 was studied in the octadecanol oxidation. The improved performance of CeO2-promoted catalysts was attributed to the high dispersion of sulfated zirconia (SZ) and the introduction of CeO2 enhancing the oxidation ability of catalysts by retarding the transformation of zirconia from highly catalytic active metastable tetragonal phase to monoclinic phase.