介孔分子筛催化合成丙烯酸正丁酯

Catalytic Synthesis of Butyl Acrylate Over Mesoporous Molecular Sieve

采用溶胶-凝胶方法,以P123为模板剂,正硅酸乙酯为硅源合成了介孔分子筛CsxH3-xPW12O40-SBA-15。XRD表征结果表明改性后的催化剂具有纯硅SBA-15分子筛晶体结构。将该催化剂用于合成丙烯酸正丁酯,并考察了不同Cs和P摩尔比对反应活性的影响,其中Cs2.5H0.5PW12O40-SBA-15的催化活性最好。采用正交设计方法确定出各因素对反应结果的影响从大到小顺序为:反应时间,反应温度,原料组成,催化剂质量分数。确定最佳操作条件:温度为130℃,酸醇摩尔比为1∶1.2,反应时间为5h,催化剂的质量分数为5%。重复试验表明Cs2.5H0.5PW12O40-SBA-15具有良好的稳定性。

By sol-gel method, mesoporous molecular sieve Cs_xH_(3-x)PW_(12)O_(40)-SBA-15 was prepared using P123 as template agent and TEOS as silicate source. XRD patterns show that the structure of Cs_xH_(3-x)PW_(12)O_(40)-SBA-15 still remains as perfect crystalline structure of SBA-15 molecular sieve. This catalyst was used for synthesis butyl acrylate. Influence of different mole ratio of Cs and P on esterification performance were focused and esterification performance of mesoporous molecular sieve Cs_(2.5)H_(0.5)PW_(12)O_(40)- SBA-15 is the best one among solid catalysts. By orthogonal experiments the following factors have ordinal inflence on the reaction: reaction time, reaction temperature, compostions of feedstock, mass fraction of the catalyst. Optimum reaction conditions are determinded as follows: reaction temperature is 130 ℃; mole ratio of acid/alcohol is 1/1.2; reaction time is 5 hours; mass fraction of catalyst to reactant is 5%. The reuse of mesoporous molecular sieve Cs_(2.5)H_(0.5)PW_(12)O_(40)- SBA-15 indicates that this catalyst has high stability under esterification conditions.