氨基酸离子液体的仲胺基功能设计及高选择性转化碳酸二甲酯过程研究

The highly efficient and selective conversion of dimethyl carbonate (DMC) to higher dialkyl carbonate is one of the most important topics in the field of carbonate research. Traditional solid base catalysts usually have some serious defects, such as small specific surface area, uneven basicity distribution, and low reactive selectivity. However, there are still few efforts in designing task-specific base catalyst for the efficient and selective conversion of DMC. In view of this situation, and on the basis of the results obtained from the pre-research in our group, it is proposed in this project to design secondary amino acid ionic liquids (SAA-ILs) and use them as novel catalysts for the highly efficient and selective conversion of DMC. Keeping this idea in mind, it is suggested to investigate the design and synthesis of SAA-ILs, the highly selective conversion of DMC in SAA-ILs, the synergistic catalysis of SAA-ILs for transesterification reaction, and also the integrated process for conversion of DMC. To look into the steps or processes mentioned above, the thermodynamics, kinetics, and process simulations are studied in detail to obtain several innovative achievements including the novel ionic liquids species, the transesterification reaction mechanism, and the integration process technology. It is believed that this project may push the technical improvement in the field of DMC research after successful implementation, and also provide the theoretical and practical basis for the production of higher dialkyl carbonate in a large scale.

碳酸二甲酯高效、高选择性地转化为长链二烷基碳酸酯是碳酸酯研究领域的热点和难点。现有固体碱催化剂存在比表面积小、碱度分布不均、反应选择性低等缺陷，为催化转化碳酸二甲酯而专门设计的碱性催化剂仍然鲜有报道。本项目经前期预研，提出用仲胺基功能设计的氨基酸离子液体催化剂（简称SAA-ILs）来创新碳酸二甲酯高效转化的新思路。围绕该思路，展开SAA-ILs的仲胺基功能设计和定向合成、SAA-ILs中长链二烷基碳酸酯的高选择性合成及串联反应动力学、SAA-ILs催化酯交换反应机理、以及基于SAA-ILs的酯交换新工艺等研究，考察过程涉及的热力学、动力学、及过程工艺特征等，以期在离子液体新物种设计、酯交换反应机理和过程集成方面取得创新性成果。本项目的实施不仅有助于促进碳酸二甲酯行业的技术发展，同时也为进一步研究长链二烷基碳酸酯的规模化制备提供重要的理论和实践基础。

长链二烷基碳酸酯是一类重要的高附加值精细化学品。现有固体碱催化剂活性较低，难以催化碳酸二甲酯高效高选择性地合成长链二烷基碳酸酯。为此，本项目设计制备出了一系列仲氨基酸离子液体、氨基多羧酸盐离子液体和1-丁基-3-甲基咪唑钨酸盐离子液体催化剂，实现了四乙基铵脯氨酸离子液体催化碳酸二甲酯高效催化转化为碳酸二丁酯，产率达到72%；实现了四乙基铵氮川三乙酸离子液体催化碳酸二甲酯高效催化转化为碳酸四氢糠二酯，产率达到79%；实现了1-丁基-3-甲基咪唑钨酸盐离子液体催化碳酸二甲酯高效催化转化为碳酸二月桂酯，产率达到99%。利用量子化学理论计算，本项目进一步阐明了仲氨基酸离子液体双位点协同催化碳酸二甲酯酯交换反应机理，建立了这三种长链二烷基碳酸酯的串联反应动力学模型并回归得到动力学参数，最终获得了绿色高效制备长链二烷基碳酸酯的过程新工艺。项目共发表SCI论文16篇，获得授权发明专利2项，培养硕士研究生毕业9名，较为圆满地完成了项目合同规定的任务。本项目的成功执行促进了碳酸二甲酯行业的技术发展，同时也为长链二烷基碳酸酯的后续工业化制备提供了重要的理论和实践基础。