碱土金属硫酸盐改性离子交换树脂催化合成醋酸丁酯

Synthesis of butyl acetate over ion exchange resin modified by alkaline earth metal sulfate

采用浸渍法对磺酸型阳离子交换树脂进行负载改性,在醋酸丁酯催化合成反应中考察离子交换树脂种类和金属盐种类对催化剂性能的影响,并运用紫外-可见漫反射光谱仪(UV-Vis)和傅里叶变换红外光谱仪(FT-IR)对改性树脂进行表征。结果表明:MgSO4和CaSO4改性的树脂催化性能较好。MgSO4改性后树脂骨架结构变化不大,特征紫外吸收峰发生红移,MgSO4与树脂的磺酸基团发生配位,形成新的催化活性中心。MgSO4的最佳负载量为5%,比未改性树脂的活性提高了30.1%。Fe3+不会影响改性后树脂的催化性能,且改性树脂重复使用5次后催化性能仍较稳定。

Modified sulfonic acid ion exchange resins were prepared by impregnation. The influences of the kind of resins and metal salts on the activity of catalyts for esterification were investigated. The prepared catalysts were characterized by ultraviolet-visible speetrophotometer （UV-Vis） and Fourier transform in- frared spectometry （FT-IR）. The results showed that the resin modified by Alkaline earth metal sulfate exhibited a better catalytic performance for esterification. Moreover, the skeleton structure of the modified resin had no change. It was observed that only a small red shift of the absorption intensity on the corre- sponding UV absorption peak took place. MgSOgcould complex with sulfonate group of rein and form the active center in the modified resin. 5 % MgSO4 modified resin was the best, and the activity increased 30. 1% compared with that of the unmodified resin. The catalytic performances of the resin modified by MgSO4 were not affected by Fe3＋. Furthermore, the modified resin showed a good repeatability after 5 times reuse.