Novel catalysts of phosphotungstic heteropolyacids （PW12） supported on neutral alumina were prepared by assistance of ultrasound and plasma treatment. The prepared catalysts were characterized by FT-IR pyridine adso...Novel catalysts of phosphotungstic heteropolyacids （PW12） supported on neutral alumina were prepared by assistance of ultrasound and plasma treatment. The prepared catalysts were characterized by FT-IR pyridine adsorption （Py-IR）, temperature programmed desorption of Pyridine （Py-TPD）, BET and X-ray diffraction （XRD）, and their catalytic performances were evaluated by the cationic polymerization of tetrahydrofuran. The results indicate that plasma treatment remarkably increases the surface acidity of the prepared catalyst while ultrasonic treatment induces PW12 to uniformly disperse on the support surface and expose more active sites for the acid catalytic reaction. A higher catalytic activity （69.7%） is obtained on the novel catalyst, which significantly outstripped that on the conventional sample （57.5%）.展开更多
A new kind of solid acid based on heteropolyacid proved be a useful catalyst in the synthesis of cyclohexyl formate.The new catalyst HPAS/TiO2-WO3 was based on heteropolyacid supported on mixed metal oxides bymicrowav...A new kind of solid acid based on heteropolyacid proved be a useful catalyst in the synthesis of cyclohexyl formate.The new catalyst HPAS/TiO2-WO3 was based on heteropolyacid supported on mixed metal oxides bymicrowave and ultrasonic method. The catalyst was characterized through TEM,TG-DTA,and IR. Data show that catalyst is very active in synthesis reaction of cyclohexyl formate even at mild temperature. Under optimal conditions,the yield of cyclohexyl formate was about 85.4%.展开更多
基金the National Natural Science Foundation of China(No.205903603)the Ministry of Sciences and Technology of China(No.2005CB221406)the New Century Excellent Talent Project of Ministry of Education of China(No.CET-05-0783)
文摘Novel catalysts of phosphotungstic heteropolyacids （PW12） supported on neutral alumina were prepared by assistance of ultrasound and plasma treatment. The prepared catalysts were characterized by FT-IR pyridine adsorption （Py-IR）, temperature programmed desorption of Pyridine （Py-TPD）, BET and X-ray diffraction （XRD）, and their catalytic performances were evaluated by the cationic polymerization of tetrahydrofuran. The results indicate that plasma treatment remarkably increases the surface acidity of the prepared catalyst while ultrasonic treatment induces PW12 to uniformly disperse on the support surface and expose more active sites for the acid catalytic reaction. A higher catalytic activity （69.7%） is obtained on the novel catalyst, which significantly outstripped that on the conventional sample （57.5%）.
文摘A new kind of solid acid based on heteropolyacid proved be a useful catalyst in the synthesis of cyclohexyl formate.The new catalyst HPAS/TiO2-WO3 was based on heteropolyacid supported on mixed metal oxides bymicrowave and ultrasonic method. The catalyst was characterized through TEM,TG-DTA,and IR. Data show that catalyst is very active in synthesis reaction of cyclohexyl formate even at mild temperature. Under optimal conditions,the yield of cyclohexyl formate was about 85.4%.
