介孔氧化铝钇负载磷钨酸催化剂制备及其催化性能

Preparation of mesoporous Al_2O_3Y-supported HPW and their catalytic behaviors

以尿素为沉淀剂,十二烷基硫酸钠为模板剂,采用均相沉淀法制备介孔氧化铝钇(Al_2O_3Y),并用浸渍法将磷钨酸(HPW)负载到Al_2O_3Y上。通过SEM、XRD、FT-IR和N_2吸附等手段对Al_2O_3Y及负载催化剂(Al_2O_3Y/HPW)进行表征。将普通Al_2O_3、介孔Al_2O_3Y和Al_2O_3Y/HPW分别催化合成十七烯基咪唑啉,结果表明,制备的介孔Al_2O_3Y为无定型,粒径(1～5)μm,平均孔径5.08 nm,最可几孔径2.25 nm,比表面积627.43 m^2·g^(-1)。磷钨酸的负载率为93.3%,热稳定性较好。在合成十七烯基咪唑啉的验证实验中,催化剂用量为反应物质量的1%,与普通Al_2O_3催化反应相比,合成反应时间缩短,反应温度降低,合成收率高出30%,可达98.2%。

Urea as the precipitating agent and SDS as the template, mesoporous Al2O3Y was prepared by homogeneous precipitation method. Phosphotungstic acid （HPW） was supported on the mesoporous Al2O3Y by impregnation method and Al2O3Y/HPW was characterized by SEM, XRD, FT-IR, N2 adsorption. Al2O3, mesoporous Al2O3 Y and Al2O3 Y/HPW were used as the catalysts for synthesis of heptadecenyimidazoline. The results showed that the as-prepared mesoporous Al2O3Y existed in amorphous phase, with grain size of （1 -5 ） μm, average pore size of 5.08 nm, most probable pore size of 2.25 nm and surface area of 627.43 m^2 · g^-1. Phosphotungstic acid loading rate was 93.3% with good thermal stability. In the heptadeceny-imidazoline synthesis experiments, with dosage of the catalyst equivalent to 1% of mass of the reactants, 30% higher yield （up to 98.2% ） than alumina was attained under shorter reaction time and lower reaction temperature.