Highly ordered hexagonal mesoporous silica SBA-15 with tunable morphology such as donut-like has been synthesized through the cosolvent approach. Donut-like SBA-15 prepared by using DMF cosolvent shows highly ordered ...Highly ordered hexagonal mesoporous silica SBA-15 with tunable morphology such as donut-like has been synthesized through the cosolvent approach. Donut-like SBA-15 prepared by using DMF cosolvent shows highly ordered circle channels and large mesopore size of 9.9 nm and pore volume of 1.45 cm3/g. Cosurfactant approach has also been used to control the morphology of SBA-15, resulting that highly ordered hard spheres (uniformed diameter—800 nm) mesoporous silica are formed. The morphology of mesoporous SBA-15 is much depended on the surface curvature energy of interface of inorganic silica and organic block copolymer species.展开更多
The molecular sieves supported TiO 2/SO 2- 4 catalyst was prepared by the liquid phase precipitation,then its preparation conditions were investigated in detail.The results indicated that the pH value of solution was ...The molecular sieves supported TiO 2/SO 2- 4 catalyst was prepared by the liquid phase precipitation,then its preparation conditions were investigated in detail.The results indicated that the pH value of solution was adjusted to 1.8,the mass ratio of TiO 2 to molecular sieves was 0.13∶100,the water in the system must be evaporated slowly at 90℃.And the best active temperature of catalyst was 50℃.The factors that had influence on the esterification of levulinic acid with alcohol were also discussed,the optimum reaction conditions were 5∶100(mass ratio) of catalyst to acid,5∶6(volume ratio) of alcohol to acid,oil bath temperature being kept at 110℃ and suitable reaction time being 1.5h.Under such conditions,the ester yield could be as high as 96.5%.展开更多
文摘Highly ordered hexagonal mesoporous silica SBA-15 with tunable morphology such as donut-like has been synthesized through the cosolvent approach. Donut-like SBA-15 prepared by using DMF cosolvent shows highly ordered circle channels and large mesopore size of 9.9 nm and pore volume of 1.45 cm3/g. Cosurfactant approach has also been used to control the morphology of SBA-15, resulting that highly ordered hard spheres (uniformed diameter—800 nm) mesoporous silica are formed. The morphology of mesoporous SBA-15 is much depended on the surface curvature energy of interface of inorganic silica and organic block copolymer species.
文摘The molecular sieves supported TiO 2/SO 2- 4 catalyst was prepared by the liquid phase precipitation,then its preparation conditions were investigated in detail.The results indicated that the pH value of solution was adjusted to 1.8,the mass ratio of TiO 2 to molecular sieves was 0.13∶100,the water in the system must be evaporated slowly at 90℃.And the best active temperature of catalyst was 50℃.The factors that had influence on the esterification of levulinic acid with alcohol were also discussed,the optimum reaction conditions were 5∶100(mass ratio) of catalyst to acid,5∶6(volume ratio) of alcohol to acid,oil bath temperature being kept at 110℃ and suitable reaction time being 1.5h.Under such conditions,the ester yield could be as high as 96.5%.
