Cu对离子液体异丁烷/丁烯烷基化反应选择性的影响研究

摘要

The Cu-containing ionic liquids ( IL), like [ BMIm] Cl-1. 8AlCl3-0. 5CuCl and [ Et3NH] Cl-1. 8 AlCl3/ CuAlCl4 , were synthesized and characterized. The selectivity of isobutene/butene alkylation of Cu-containing IL was also investigated. The results showed that the selectivity had little relation to the acidity of Cu-containing IL. The research octane number (RON) of [Et3NH]Cl-1. 8AlCl3/CuAlCl4 alkylate could be higher than 100, which was better than those obtained by sulfuric acid, common chloroaluminate IL, and composite IL under the identical reaction conditions. The complexation of CuAlCl4 with 2-butene in alkylation process should be accounted for the super selectivity of trimethylpentane ( TMP ) of isobutane alkylation catalyzed by Cu-containing IL.%合成并表征了[BMIm]Cl-1.8AlCl3-0.5CuCl、[Et3NH]Cl-1.8AlCl3/CuAlCl4等离子液体,考察了含Cu离子液体等酸性催化剂中的异丁烷/丁烯烷基化反应,研究了Cu对离子液体烷基化选择性的影响。结果表明,Cu的引入对离子液体酸性的影响较小,不是反应选择性提高的主要原因,而烷基化过程中CuAlCl5-/CuAlCl4等配合物的存在,以及它们对2-丁烯的络合吸附是改善离子液体催化选择性的关键因素。相同反应条件下,[Et3NH]Cl-1.8AlCl3/ CuAlCl4、[BMIm]Cl-1.8AlCl3/CuAlCl4等催化剂的三甲基戊烷选择性最高可达87.5%(质量分数),产物辛烷值100.5,明显优于硫酸、常规氯铝酸离子液体和复合离子液体等烷基化汽油辛烷值。