Micellar Catalysis for Propene Epoxidation
|School||Hebei University of Technology|
|Keywords||propene oxide micellar catalysis propene propane dehydrogenation|
The propane dehydrogenation was studied in tubular fixed reactor system. The micellar catalysis for propene epoxidation was studied in 300mL stainless steel gas-liquild stirred reactor, both C3H8-C3H6-H2 and propene being used as feedstocks. The micellar catalysis structure was characterized by UV-vis spectrophotometer. The products were analyzed by gas chromatography.Experimental results of propane dehydrogenation indicated that among Pt/γ-Al2O3, Pt-Na/γ-Al2O3 and Pt-Sn-Na/γ-Al2O3, Pt-Sn-Na/γ-Al2O3 exhibited the optimum catalysis performance under the reduction temperature 450℃and reduction time 2 hours.The reaction conditions in propane dehydrogenation by Pt-Sn-Na/γ-Al2O3 catalysis were optimized. When temperature was 580℃, the flow of propane was 40mL/min,the amount of catalyst was 2g and the conversion of propane was 33.25%,the selectivity of propene reached 84.62% and the yield of propene was 28.14%.The solubilization experiment of manganene porphyrin in surfactants solution indicated that TX-100 exhibited better solubility to manganene porphyrin.The location experiment of micelle-incorporated manganese porphyrin by UV-vis method indicated that manganese porphyrin was solubilized in the palisade layer of micelle.Experimental results of micellar catalysis system indicated that too high H2O2 concentration was unfavorable to formation of PO resulting from competive adsorption of H2O2 and C3H6 on the manganene porphyrin molecule.A suitable catalysis system conditions were the concentration of manganese porphyrin was 1mmol/L,the concentration of H2O2 was 20mmol/L, the molar ratio of imidazole to manganese prophyrin was 12:1,the concentration of surfactant was 60mmol/L,the flow of propene was 50mL/min and reaction temperature was 30℃, the utlization of H2O2 was 11.8%,the yield of PO was 4.9%. PO was not detected in the experiment of micellar catalysis for propene epoxidation which C3H8-C3H6-H2 was used as feedstock.