含铈化合物催化氨基甲酸甲酯和甲醇合成碳酸二甲酯

Synthesis of Dimethyl Carbonate from Methyl Carbamate and Methanol by Catalyzed by Cerium Compounds

以氨基甲酸甲酯(MC)和甲醇为原料、含铈化合物为催化剂,在反应釜中合成了碳酸二甲酯(DMC)。实验结果表明,在相同实验条件下,Ce(NO3)3具有最佳的催化活性。以Ce(NO3)3为催化剂,考察了反应条件(催化剂用量、反应温度和反应时间等)对合成DMC反应的影响。实验结果表明,在MC7.5g、甲醇64g、反应温度180℃、反应时间8h、催化剂用量0.5g的优化条件下,MC转化率为73.95%,DMC收率可达44.94%。FTIR表征结果进一步说明,三价铈离子能与MC酰胺基上的氧原子配位,可高效活化MC分子,所形成的中间体能进一步和甲醇分子反应,从而促进DMC的合成。

Various cerium compounds were used as catalysts for synthesis of dimethyl carbonate （DMC） from methyl carbamate（MC） and methanol in a batch reactor. Evaluation results showed that cerium nitrate among the catalysts possessed the best catalytic performance under the same conditions. Besides, effects of reaction conditions in the synthesis on the catalyst properties were investigated. It was concluded that under optimal reaction conditions： MC 7.5 g, methanol 64 g, reaction temperature 180 ℃, reaction time 8 h and catalyst dosage 0.5 g, MC conversion and DMC yield were 73.95 % and 44.94%, respectively. Furthermore, based on FFIR results, the trivalent metallic ions Ce3＋ could coordinate with the oxygen atoms of amide groups in MC molecules. Then the intermediate could interact with methanol molecules easily, which could promote the DMC synthesis.