固体碱在二氧化碳-甲醇法合成碳酸二甲酯反应中的作用

The Role of Solid Base Played in Direct Synthesis of Dimethyl Carbonate from CO_2 and Methanol

本文探讨了固体碱的制备和预处理等因素对于ＣＯ_２~－甲醇法合成碳酸二甲酯（ＤＭＣ）的影响，发现微波法所制碱性沸石等多孔材料的反应活性高于浸渍法所制样品。本文首次报道了微波辐射低压合成ＤＭＣ的新方法，该法能极大地缩短反应时间并提高产物选择性。研究表明： ＣＯ_２和甲醇生成 ＤＭＣ的反应在热力学上是几乎不能进行的，加入固体碱的实质是提供了一条耦合的途径。

Microwave irradiation and impregnation were employed to prepare basic zeolites and other porous materials, and the activities of these samples were examined in the direct synthesis of dimethyl carbonate (DMC) from CO_2 and methanol. The samples prepared by microwave irradiation exhibited a higher activity than those did by impregnation. Direct synthesis of DMC in the microwave field was first reported. This method shortened the reaction time effectively and brought a high CH_3OCH_3 for this reaction since there was almost no by-product CH_3OCH_3 formed. Finally the mechanism of this synthesis was also explored in the terms of thermodynamics. According to thermodynamically analysis this reaction could hardly proceed. The purpose of adding solid base was to provide a coupling way instead of a catalyst.