论文部分内容阅读
二苄基甲苯是一种性能优良的合成高温导热油,其典型的合成方法是Friedel-Crafts烷基化反应。Friedel-Crafts烷基化反应需要使用酸性催化剂,但传统的液体催化剂存在腐蚀性强,分离困难等缺陷。用沉淀法制备的SO_4~(2-)/TiO_2固体超强酸催化剂解决了腐蚀性和分离困难的问题,并具有良好的催化活性。对单苄基甲苯和氯化苄合成二苄基甲苯的反应条件进行了研究。考察了SO_4~(2-)/TiO_2固体超强酸催化剂用量,反应温度,反应时间和单苄基甲苯/氯化苄摩尔比对氯化苄转化率和二苄基甲苯选择性的影响。适宜的反应条件为SO_4~(2-)/TiO_2固体超强酸催化剂用量1.6%质量分数,反应温度为100℃,反应时间为3 h,单苄基甲苯/氯化苄的摩尔比为5。在该合成条件下,氯化苄的转化率达到99%,二苄基甲苯的选择性达到88%。合成的二苄基甲苯可用作高温导热油。
Dibenzyltoluene is an excellent synthetic high-temperature heat-conducting oil. The typical synthesis method is Friedel-Crafts alkylation. Friedel-Crafts alkylation reaction requires the use of acidic catalyst, but the traditional liquid catalyst is corrosive, separation difficulties and other defects. The SO_4 ~ (2 -) / TiO_2 solid superacid catalyst prepared by precipitation method has solved the problem of corrosion and separation difficulties and has good catalytic activity. The reaction conditions of synthesizing dibenzyltoluene from monobenzyl toluene and benzyl chloride were studied. The effects of the amount of SO_4 ~ (2 -) / TiO_2 solid superacid catalyst, the reaction temperature, the reaction time and the molar ratio of monobenzyl toluene / benzyl chloride on the conversion of benzyl chloride and the selectivity of dibenzyltoluene were investigated. The suitable reaction conditions were the mass fraction of SO 4 2- / TiO 2 solid superacid catalyst 1.6%, the reaction temperature 100 ℃, the reaction time 3 h and the molar ratio of monobenzyl toluene / benzyl chloride 5. Under this synthetic condition, the conversion of benzyl chloride reached 99% and the selectivity of dibenzyltoluene reached 88%. Synthetic dibenzyltoluene can be used as a high temperature heat transfer oil.