纳米H_3PW_(12)O_(40)/SiO_2复合杂多酸催化合成乙酸正戊酯

Synthesis of n-Amyl Acetate Catalyzed by Nano-Silica Supported Phosphotungstic Acid

采用溶胶-凝胶法制备了纳米H3PW12O40/SiO2复合杂多酸,并以其催化合成乙酸正戊酯,研究了催化剂用量、反应时间、反应温度、酸醇摩尔比等对酯化反应的影响,考察了纳米H3PW12O40/SiO2复合杂多酸催化剂的重复使用性能,并将其催化性能和磷钨酸进行了比较。结果表明,在冰乙酸用量为0.05mol、酸醇摩尔比为1∶1.8、催化剂用量(以反应物总质量计)为4.6%、反应时间为1.5h、反应温度约130℃左右、带水剂环己烷用量为10mL的优化条件下,乙酸正戊酯的产率达91.1%。纳米H3PW12O40/SiO2复合杂多酸催化剂的循环使用性能较理想;以纳米H3PW12O40/SiO2催化合成乙酸正戊酯的效果比直接用磷钨酸的效果好。

The nano-silica supported phosphotungstic acid H3 V＇Wn 1340/bIU2 was preparea oy sot-gel IIIeLIIUU and was applied to the synthesis of n-amyl acetate. The effects of catalyst dosage, reaction time, reaction temper- ature, molar ratio of acetic acid to n-amyl alcohol on the esterification reaction were explored. Under the opti mum synthetic conditions as follows：the acetic acid amount was 0.05 tool,the molar ratio of acetic acid to n-am yl alcohol was 1：1.8,the catalyst dosage was 4. 6% of total mass of the reactants,the reaction time was 1.5 h, the reaction temperature was about 130 °C, the cyclohexanol amount was 10 mL, the yield of n-amyl acetate reached 91.1 %. The reusability performance of H3PW12 O40/SIO2 was perfect,and its catalytic performance was better than that of H3PWlzO40.