Incorporation of tungsten oxide in mesoporous silica: Catalytic epoxidation of olefins using sodium-bi-carbonate as co-catalyst

Tungsten oxide incorporated mesoporous molecular sieve (WO3–SBA-15) composite was successfully synthesized via one-step hydrothermal process using tetraethylorthosilicate (TEOS) as the silica source, sodium tungstate as the tungsten precursor, and pluronic P123 triblock polymer (EO20PO70EO20, Mav = 5800) as a structure-directing agent. The material was characterized by small angle X-ray diffraction (SAX), transmission electron microscopy (TEM), nitrogen sorption measurement and Fourier transform infrared spectroscopy. The catalyst showed excellent catalytic efficiency in epoxidation reactions with various olefinic compounds using H2O2 as oxidant and NaHCO3 as co-catalyst. The solid catalyst can be recovered after reaction and can be reused for several times in catalytic reactions without any significant loss of activity.