摘要
采用化学接枝法将不同阴阳离子的酸性离子液体负载在MCM-36分子筛表面进行改性，合成了一系列负载离子液体型固体酸催化剂。通过。HNMR、XRD、FTIR、TG、BET及表面酸量测试对改性分子筛的基础特性进行了表征，并考察了催化剂对乙酸乙酯合成反应的催化特性。表征结果显示，离子液体的负载对MCM-36分子筛基体的晶相结构未产生破坏，催化剂仍保留原有的层状柱撑结构，孔道特性相对较好，且具有良好的热稳定性。通过控制离子液体负载量和改变离子液体的阴阳离子结构均可有效地调控催化剂的表面酸量。实验结果表明，以离子液体3-磺酸丁基-1-（3-三乙氧基硅）丙基咪唑硫酸氢盐对MCM-36分子筛进行负载改性后，在100℃、4h、m（催化剂）：m（乙酸）=0．05、n（乙醇）：n（乙酸）=2的条件下，乙酸转化率为84．42％，乙酸乙酯选择性达100％。经5次重复利用后仍具有与MCM-36分子筛相当的催化活性，且乙酸乙酯的选择性仍可达100％。
A series of solid acid catalysts（IL-MCM-36） were synthesized by grafting acidic ionic liquids onto MCM-36 molecular sieve. The catalysts were characterized by means of 1H NMR, XRD, FTIR, TG and BET. The acidities of the catalysts were measured by N-butylamine titration method. Their catalytic activities in the synthesis of ethyl acetate were investigated. It was showed that, the crystal structure of MCM-36 was not destroyed by supporting the ionic liquids, the layered structure was kept, and the solid catalysts with better pore characteristics and thermostability were obtained. It was indicated that the surface acidity of the catalysts could be adjusted by controlling the loading of the ionic liquids and the structure of ions in the ionic liquids. Under the conditions of MCM-36 grafted with 3-sulfobuty-l-（3-popyltriethoxysilane）imidazdium trifluoromethane sulfonate as catalyst, reaction temperature 100 %, reaction time 4 h, m（catalyst） ： m（acetic acid） 0.05 and n（ethanol） ： n（acetic acid） 2, the conversion of acetic acid and the selectivity to ethyl acetate reached 84.42% and 100%, respectively. After it was reused five times, the selectivity to ethyl acetate still reached 100% and the conversion of acetic acid was almost equivalent to that over the MCM-36 catalyst.
出处
《石油化工》
CAS
CSCD
北大核心
2016年第10期1172-1179,共8页
Petrochemical Technology
基金
国家自然科学基金项目(21276163
21576168)
