Nanoporous silica-supported nanometric palladium: synthesis, characterization, and catalytic deep oxidation of benzene.

In this present study, nanoporous silica SBA-15 supported palladium catalysts are prepared through two different methods. The catalysts are employed for catalytic deep oxidation reaction of benzene at a high gas hourly space velocity of 100,000 h(-1). It is found that the traditional aqueous impregnation method has some difficulties and disadvantages in obtaining highly dispersed palladium active phases. Whereas, when a grafting procedure is employed, palladium tends to be highly dispersed as nanoparticles due to the confinement of the nanosized pore channels of the support materials. The catalysts prepared via the grafting procedure catalyze the benzene oxidation far more effectively than those prepared via aqueous impregnation method, and complete conversion of benzene can be achieved below 190 degrees C over the most active catalyst. The nanoporous silica-supported palladium catalysts are promising materials for the control of some types of VOCs such as benzene.