复合介孔氧化铝在乙氧基化反应中的催化性能

Catalytic Performance of Aluminium Based Dodecyl Sulfate Mesophase for Oxyethylation of Dodecanol

以乙二胺为碱性介质合成了氧化铝/十二烷基硫酸钠复合介孔氧化物(AlOS),该复合介孔氧化物具有六方介孔结构特征和中强酸度,其平均孔径为2.8 nm,比表面积为245 m^2/g。考察了氧化铝/十二烷基硫酸钠复合介孔氧化物在十二醇乙氧基化反应中的催化特性。结果表明,AlOS在脂肪醇乙氧基化反应中具有较高催化活性,而且产物分子量分布较窄。升高反应温度、增加初始压力和提高催化剂用量,乙氧基化反应速率增加。当反应温度为140℃,初始压力为0.6 MPa,催化剂用量为十二醇用量的10.0%时,十二醇与环氧乙烷的反应速率常数约为0.036 min^(-1)。当环氧乙烷平均聚合度为4.0时,十二醇聚氧乙烯醚分子量分布选择性系数达到18.

Aluminium-based dodecyl sulfate mesophase （AlOS）, which had hexagonal structure, middle-strength acid sites, 2.8 nm pore diameter and 245 m^2/g specific surface area, was synthesized by using ethylenediamine as alkali agent. The catalytic properties of AlOS for oxyethylation of dodecanol and ethylene oxide （EO） were investigated. The results showed that AlOS exhibited high catalytic activity for oxyethylation with narrow molecular distribution. With the increasing of temperature, initial pressure and AlOS dosage, reaction rate of oxyethylation increased. The reaction rate constant of dodecanol and EO was 0. 036 min^-1 under initial pressure 0.6 MPa and mass ratio of AlOS to dodecanol 10.0% at 140 ℃. The distribution selectivity coefficient of dodecanol polyoxyethylene ether was 18. 79 when the average degree of oxyethylation of EO was 4. 0.