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

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.