酯交换法合成碳酸二甲酯的催化剂研究

用ＺＳＭ－５分子筛作为甲醇和碳酸乙烯酯反应碳酸二甲酯 系的催化剂，通过对ＺＳＭ－５进行阳离子交换和浸渍法改性发现，ＺＳＭ－５分子筛碱性中心对反应起主要作用，适当强度的碱中心更有利于反应的正向进行。当甲 碳酸 乙酯的摩尔比为４：１，液时空速１ｍｌ／ｇｈ，反应温度１００℃，压力０．７ＭＰａ时，用碳酸钠改改性ＺＳＭ－５作催化剂，碳酸乙烯酯的转化率为５０％。

Study on Catalysts for Transesterification Synthesis of Dimethyl Carbonate

ZSM-5 molecular sieve was used as catalyst for transesterification synthesis of dimetf1yl carbonate with methanol and ethylene carbonate. Modification of ZSM - 5 by positive ion exchange and impregnation indicated that the base sites in the molecular sieve were the major factors affecting the transesterification activity,and moderate base strength showed much better performance. When reaction conditions are as follows: molar ratio of methanol and ethylene carbonate 4: 1, liquid airspeed 1 ml/gh, reaction temperature 100t, pressure 0. 7MPa, and ZSM - 5 modified by sodium carbonate is used as catalyst,conversion ratio of ethylene carbonate is about 50%.