Abstract:
Propylene oxide (PO) is an important industrial intermediate, which has traditionally been produced by the epoxidation of propylene using hydroperoxide or epichlorohydrin processes. The direct vapor-phase epoxidation of propylene, in the presence of oxygen and hydrogen, is the more environmentally friendly process. The selectivity to PO over gold supported on alumina, zinc oxide, and titania catalysts were investigated. The catalysts were prepared by sol-gel, deposition-precipitation, and co-precipitation methods. The reactions were carried out between 40 and 200℃ with different feed compositions. The catalysts were characterized by BET, XRD, and AAS measurements. The result showed the highest surface area of about 450 m2/g for gold supported on alumina catalysts, while the gold supported on titania and zinc oxide catalysts were about 70 and 50 m2/g respectively. The Au/A12O3 and Au/ZnO catalysts showed almost no selectivity to PO and produced only CO2 and propane as major products. Au/TiO2 catalysts prepared by sol-gel method showed high selectivity and production rate of PO at the reaction temperature of 80℃.
