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›› 2007, Vol. 7 ›› Issue (3): 476-482.

• 反应与分离 • 上一篇    下一篇

铜基络合催化剂液相羰基合成碳酸二甲酯

杨洋,刘晓勤,刘定华,姚虎卿   

  1. 南京工业大学化学化工学院
  • 出版日期:2007-06-20 发布日期:2007-06-20

Dimethyl Carbonate Synthesis by Oxidative Carbonylation with CuBr3L2 Catalyst

YANG Yang,LIU Xiao-qin,LIU Ding-hua,YAO Hu-qing   

  1. College of Chemical and Chemistry Engineering, Nanjing University of Technology
  • Online:2007-06-20 Published:2007-06-20

摘要: 制备了甲醇液相羰基化法合成碳酸二甲酯(DMC)的新型CuBr3L2络合催化剂,该催化剂具有较高的催化活性与稳定性. XPS和EPR表征发现添加配位剂四丁基溴化铵(简称L)有助于表面活性物种Cu(I)的形成. 采用正交实验设计对工艺条件进行优化,在温度373~383 K、压力3.0~3.5 MPa、时间4~6 h、催化剂浓度(以甲醇的体积计) 0.15~0.20 g/mL的工艺条件范围内,甲醇转化率可达到23%,DMC选择性大于95%. 动力学研究表明,该反应是一个近似二级反应,反应表观速率常数Kp与催化剂质量浓度和反应温度有关,且Kp与催化剂浓度的平方成正比. 高温高压不利于主反应的进行,导致目的产物选择性下降.

关键词: 碳酸二甲酯, 四丁基溴化铵, 甲醇, 氧化羰化, 液相, 动力学

Abstract: A new type of CuBr3L2 complex catalyst for dimethyl carbonate (DMC) synthesis by oxidative carbonylation of methanol in liquid-phase was reported. The complex catalysts were characterized by means of XPS and EPR. The results showed that the introduction of complexing agent tetrabuthylammonium bromide (L) can promote the substantial formation of Cu(I) species for DMC synthesis. With the method of orthogonal experiment, the process conditions (temperature, concentration of catalyst, pressure and reaction time, etc.) were examined. The results indicated that under the optimum conditions (temperature 373~383 K, pressure 3.0~3.5 MPa, reaction time 4~6 h, concentration of catalyst in methanol 0.15~0.20 g/mL), the conversion rate of methanol could reach 23% and the selectivity of DMC could exceed 95%. The reaction kinetics with CuBr3L2 complex catalyst for DMC synthesis was investigated. The kinetic equation and parameters were obtained. The results showed that the reaction of methanol oxidative carbonylation to DMC by the catalyst was an second order reaction approximately. The reaction rate constant (Kp) was related to reaction temperature and mass concentration of catalyst, and Kp was directly proportional to the square of mass concentration of catalyst. It was indicated that high temperature and pressure were unfavorable to the main reaction and caused the decrease of DMC selectivity.

Key words: dimethyl carbonate, tetrabuthylammonium bromide, methanol, oxidative carbonylation, liquid phase, kinetics