改性SBA-15催化剂用于棕榈酸甲酯脱氧提质

Modified SBA-15 catalysts for methyl palmitate decarboxylation

摘要:

以水热稳定性高的Al-SBA-15介孔分子筛为载体，负载CuO制备了CuO/Al-SBA-15催化剂，并采用一步合成法制备出Fe-Al-SBA-15催化剂，对其进行了XRD、TEM及FTIR等测试及表征。以Al-SBA-15、CuO/Al-SBA-15及Fe-Al-SBA-15为催化剂，进行棕榈酸甲酯的非临氢脱氧反应。结果表明：CuO在介孔材料表面均匀分散，三种催化剂中CuO/Al-SBA-15的脱氧效果最好，确定最佳反应条件为反应温度342 ℃，反应时间2 h。与未加催化剂相比，在最佳反应条件下，棕榈酸甲酯脱羧产生烃类的选择性提高了40~60 %。催化剂重复使用3次，棕榈酸甲酯的转化率无明显下降。根据活性评价推测脱羧反应机理为：在亚临界水中棕榈酸甲酯水解生成棕榈酸，在催化剂的活性中心上羧酸根负离子形成羧基化物，之后被活化氢进攻临近羧基的C-C键，进而CO2脱附下来，生成主产物十五烷。

Abstract:

In this paper, CuO / Al-SBA-15 catalyst was prepared by supporting CuO on highly hydrothermal stable Al-SBA-15 mesoporous molecular sieve. The Fe-Al-SBA-15 catalyst was prepared by one-step synthesis method. XRD, TEM and FTIR were used for characterizations of the catalysts. The non-hydrodeoxygenation of methyl palmitate was carried out on Al-SBA-15, CuO / Al-SBA-15 or Fe-Al-SBA-15. The results showed that the metal oxides were uniformly dispersed on the surface of the mesoporous material, and CuO / Al-SBA-15 gave the best deoxygenation performance, the optimum reaction conditions were 342 ℃ and 2 h reaction time. Under optimum reaction conditions, the selectivity of decarboxylation of palmitic acid methyl ester are 40 ~ 60% higher than that of the non-catalytic reaction. The CuO / Al-SBA-15 catalyst was reused three times and the conversion of methyl palmitate revealed no significant reduction. According to the activity evaluation, it was deduced that the decarboxylation mechanism was as follows: Palmitic acid was produced by hydrolysis of methyl palmitate in the subcritical water, carboxylate was formed on the active center of the catalyst through next the C-C bond near the carboxyl group was attacked by activated hydrogen, and then CO2 desorpted and the main product pentadecane derived.