咪唑类化合物-CuCl络合催化剂在甲醇氧化羰基化反应中的催化性能

研究了咪唑及其衍生物配合CuCl对甲醇液相氧化羰化合成碳酸二甲酯的催化性能。筛选出溶解性好、腐蚀性小且催化活性高的多功能助催剂。实验结果表明，反应体系中加入N-甲基咪唑后，CuCl可以完全溶解。当催化剂的浓度为0.2 mol/L, N-甲基咪唑与CuCl的量为4∶1，反应温度为120 ℃，反应压力为2.40 MPa，CO与O2的进气比2∶1，反应3 h的条件下甲醇的摩尔转化率为15.4%，选择性为98%以上。从腐蚀性试验结果看，50 ℃时，加入N-甲基咪唑化合物后，Q235钢在CuCl/CH3OH/H2O/CO/O2体系中的腐蚀速率为0.22mm/a，缓蚀效率为94.5%。动力学研究表明，反应近似为一级，加入N-甲基咪唑后，反应速率常数为0.15 min－1。

STUDIES ON CATALYTIC PROPERTIES OF COMPLEXES OF IMIDAZOLE DERIVATES WITH CuCl FOR OXIDATIVE CARBONYLATION OF METHANOL

The catalysis of copper complexes bearing ligands of imidazole and derivative compounds is systematically studied in the reaction of oxidative carbonylation of methanol to dimethyl carbonate. The best multifunctional promoter N-methylimidazole，which has better performance on solubility, inhibition of corrosion and promoting catalysis for oxidative carbonylation has been found. The experiments show that cuprous chloride could be solved completely after adding N-methylimidazole to liquid methanol. It will be very useful in the application of this new catalytic system in production of dimethyl carbonate. The molar conversion of methanol and selectivity of dimethyl carbonate was 15.4x% and 98s%. respectively when the reaction was carried out under 120 ℃, 2.4 MPa, pCO/pO2=2∶1, CCuCl=0.2 mol/L,CNMI/CCuCl=4∶1, and reaction time 3 h. The corrosion experiment was carried out in CuCl/NMI /CH3OH/H2O liquid system at 50 ℃ and 0.1 MPa of CO/O2(molar ratio 2∶1) reaction gas atmosphere.The corrosion rate of Q235 steel in the reaction system is 0.22 mm/a and the inhibition efficiency is about 94.5%. The kinetic study shows that the reaction is almost first order for the N-methylimidazole/CuCl catalytic system, and the rate constant is about 0.15 min－1.