Sn-MCM-22分子筛催化DHA制备乳酸酯

Synthesis of alkyl lactates with DHA catalyzed by Sn-MCM-22

摘要:

以MCM-22分子筛为原料，采用SnCl4对其后处理改性合成了Sn-MCM-22催化剂，用于催化1,3-二羟基丙酮（DHA）与醇制备乳酸酯。XRD、SEM、N2吸附-脱附、UV-vis和Py-IR表征结果显示：Sn以嵌入分子筛骨架和SnO2接枝方式改性MCM-22，改性催化剂具有强Lewis和Brønsted复合双酸性位点，有效催化DHA制备乳酸酯。催化反应结果表明：选用Sn-MCM-22催化剂催化DHA甲醇溶液（0.25mol/L），反应温度120℃，反应时间15 h，乳酸甲酯收率达96.3%。催化剂催化DHA与乙醇、正丙醇、正丁醇反应，相应的乳酸酯收率达到86.4%~88.4%，催化剂具有良好的循环稳定性。

Abstract:

Sn-MCM-22 catalysts were synthesized using a post-synthetic method of MCM-22 zeolite with SnCl4 for converting 1,3-dihydroxyacetone (DHA) and alcohol to alkyl lactates. The characterization results of XRD, SEM, N2 adsorption-desorption, UV-Vis, Py-IR demonstrated that Sn was incorporated into the tetrahedral framework and uniformly grafted as SnO2 nanoparticles on Sn-MCM-22. Sn-MCM-22 possessed Lewis and Brønsted acid sites, and effectively catalyzed DHA to prepare alkyl lactates. The yield of methyl lactate reached 96.3 %, under the conditions: DHA methanol solution (0.25 mol/L), the reaction temperature was 120 oC, and the reaction time was 15 h. In addition, the high yields of alkyl lactates, up from 86.4% to 88.4%, were produced from ethanol, n-propanol, and n-butanol, respectively. The catalyst displays good cycling and stability performance.