固体酸催化剂SO42-/TiO2-SnO2的合成及其催化合成丙烯酸异冰片酯

Preparation of SO42-/TiO2-SnO2 Solid Acid Catalyst and Its Catalytic Activity in Isobornyl Acrylate Synthesis

采用共沉淀与浸渍法制备了不同SnO2掺杂量（摩尔分数1%-7%,以TiO2计,下同）的SO4^2-/TiO2-SnO2固体酸催化剂,利用N2-吸附脱附、FTIR、NH3-TPD对催化剂的结构和性质进行了表征。结果表明：SnO2掺杂可以有效改善催化剂的比表面积与孔结构,有利于载体与SO4^2-形成配位结构,显著增加了催化剂酸性中心数量,从而增强了催化性能。SnO2掺杂量为5%的SO4^2-/TiO2-SnO2固体酸催化剂催化丙烯酸与莰烯酯化反应,催化剂用量为10%（占反应物的质量分数,下同）,反应温度为70℃,丙烯酸与莰烯物质的量比为1.3︰1时,莰烯的转化率为81.9%,丙烯酸异冰片酯选择性为98.5%,较SO4^2-/TiO2显示出更高的反应活性与稳定性。

A series of SnO2-doped （doping amount from 1% to 7%, based on the mole of TiO2） SO4^2-/TiO2-SnO2 catalysts were prepared by co-precipitation and impregnation methods. The structures and properties of these catalysts were characterized by NE-adsorption and desorption, FTIR and NH3-TPD. The result showed that SnO2-doping could not only effectively improve the specific surface area and pore structure of catalyst, but also be favorable for the formation of coordination structure between carrier and SO2-. Meanwhile, SnO2-doping could obviously increase the amount of acid center on surface, which resulted in the enhancement of the catalytic activity. The solid acid catalyst, SO2-/TiO2-SnO2, doped with 5% molar fraction of SnO2 was used to catalyze the esterification reaction between acrylic acid and camphene. Under the reaction conditions of catalyst dosage of 10% on the basis of the total mass of reactants, reaction temperature of 70℃, and the molar ratio of acrylic acid and camphene of 1.3 ： 1, the conversion of camphene was 8 1.9% and the selectivity of isobomyl acrylate was 98.5%. SO4^2-/TiO2-SnO2 had higher activity and stability than SO4^2-/TiO2.