Al-SBA-15固体酸催化合成硬脂酸三乙醇胺酯

Synthesis of Stearic Acid Triethanolamine Ester over Solid Acid Catalyst Al-SBA-15

摘要:

制备了一系列Si/Al比从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 mgKOH/g，单双酯总含量可达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Br鴑st酸。

Abstract:

Al-SBA-15 solid acid catalysts with Si/Al ratio ranging from 15 to 50 were prepared and used for the catalysis of esterification of stearic acid with triethanolamine. The Al-SBA-15 (Si/Al=25) catalyst exhibited high activity and selectivity in the esterification, the acid value of the esteramine were reduced to 1.78 mgKOH/g and content of mono-esteramine and di-esteramine reached 84.79%. The activity of Al-SBA-15 (Si/Al=25) was not obviously changed when the catalyst reused 6 times. The results indicated that the catalyst showed good stability during the esterification reaction. The structure and acidity of the catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms (BET), transmission electron microscopy (TEM) and pyridine in situ FTIR. These results showed that Al-SBA-15(Si/Al=25) kept the structure of SBA-15, and had large surface area, uniform channels, and the same time Lewis and Brønst acid sites were presence on the surface of the catalysts.