离子液体中乙炔氢氯化液相反应体系的研究

Liquid Phase Reaction System for Hydrochlorination of Acetylene in Ionic Liquids

寻找合适的反应介质一直制约着乙炔氢氯化液相反应体系的发展,离子液体作为一类蒸汽压低、热稳定性高的新型绿色介质为乙炔氢氯化液相反应提供了新思路。本工作首先研究了非汞催化剂与离子液体1-丁基-3-甲基咪唑氯盐([Bmim]Cl)组成的催化体系,考察了温度、流速和金属催化剂种类对催化活性的影响,进而研究了离子液体结构对PdCl_2/离子液体体系催化活性的影响。在此基础上,构建得到了一类低成本且高效的PdCl_2/质子酸离子液体体系,并首次将其应用于乙炔的氢氯化反应,在反应温度180℃,乙炔流速5 mL/min,氯化氢与乙炔的流速比1.2,PdCl_2的摩尔浓度为0.04 mol/L的条件下,体系中的乙炔转化率可达75%,氯乙烯选择性高于99.3%,且在反应6 h时间内具有很好的稳定性,作为一类绿色非汞催化剂体系,具有较好的研究前景。

Looking for suitable media is a critical factor that imposes great restriction on the evolution of gas-liquid acetylene hydrochlorination reaction.Ionic liquids（ILs） as green media due to negligible vapor pressure and good thermal stability have provided new approach for this kind of reaction.In this study,catalytic systems consisting of non-mercuric catalysts and l-butyl-3-methylimidazolium chloride ionic liquids（（[Bmim]Cl） for acetylene hydrochlorination were explored.The effects of temperature,flow rate and metal catalyst species on the catalytic activity in[Bmim]Cl system were studied and further the influence of the structure of ILs on the performance of PdCl_2/IL systems was investigated.On the above basis,a series of low-cost and efficient PdCl_2/protonic IL systems were developed and was firstly applied in acetylene hydrochlorination reaction.Result showed that acetylene conversion of about 75%and vinyl chloride selectivity of above 99.3%can be obtained in the PdCl2/protonic IL systems under the reaction temperature of 180 ℃,acetylene flow rate of 5 mL/min when the flow rate ratio of HC1 to C_2H_2 was at 1.2 and PdCl_2molar concentration was 0.04 mol/L.Good reaction stability was observed over 6 h.This green non-mercuric catalytic system for hydrochlorination of acetylene looks promising for further study.