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制备了一系列Si/Al比(均为摩尔比,下同)从15到50的Al-SBA-15固体酸催化剂,并将其应用于硬脂酸与三乙醇胺的酯化反应中。结果表明,Si/Al比为25的Al-SBA-15固体酸催化剂的催化活性和选择性较高,反应6 h酯胺的酸值可降至1.78 mg KOH/g,单双酯总质量分数可达84.79%;该催化剂重复使用6次,催化活性没有明显降低,说明该催化剂具有高的稳定性。采用XRD、N2吸附脱附、透射电镜和吸附吡啶的红外光谱对催化剂的结构、比表面积和表面酸性进行了表征,结果表明,Si/Al比为25的Al-SBA-15催化剂保持了SBA-15的结构,具有大的比表面积和均一的孔径,在催化剂表面同时存在Lewis酸和Brnsted酸。
A series of Al-SBA-15 solid acid catalysts with Si / Al ratio (both molar ratio, the same below) from 15 to 50 were prepared and applied to the esterification of stearic acid with triethanolamine. The results show that the catalytic activity and selectivity of Al-SBA-15 solid acid catalyst with Si / Al ratio of 25 are high, the acid value of ester amine at 6 h can be reduced to 1.78 mg KOH / g, the total mass fraction of monoester and diester Up to 84.79%. The catalyst was reused 6 times without any significant decrease in catalytic activity, indicating that the catalyst has high stability. The structure, specific surface area and surface acidity of the catalyst were characterized by XRD, N2 adsorption-desorption, transmission electron microscopy and pyridine adsorption. The results showed that the Al-SBA-15 catalyst with Si / Al ratio of 25 kept the SBA- 15 structure, with a large specific surface area and uniform pore size, the presence of Lewis acid and Brnsted acid on the catalyst surface.