双功能离子液体催化剂设计及其催化羟醛缩合反应机理研究

The aldol condensation of formaldehyde and propaldehyde is the critical step in the process of methyl methacrylate production from C2 and syngas. Traditional catalyst for aldol condensation has much disadvantage such as inefficiency, strongly corrosive and difficult to recycle. High efficiency catalyst for the aldol condensation of formaldehyde and propaldehyde and the reaction mechanism research is urgent need for the development of this clean process for methyl methacrylate production. In this project, acid-base ionic liquids will be designed and prepared through changing the anion type, group and the structure of cation, in order to attain the rule between the acid-base degree and the types of ionic liquids. The cid-base degree of ionic liquids will be revised to get high efficiency bifunctional ionic liquid catalyst for the aldol condensation of formaldehyde and propaldehyde. Combining in-suit detection method with molecular simulation, the activation of α-H and the reaction mechanism in the aldol condensation will be studied. This will give theoretical support for the critical technique to cleanly produce methylacrolein and methyl methacrylate. Also this is good for the modification of aldol-condensation catalyst and the extensive application of aldol condensation reaction in theory.

甲醛与丙醛羟醛缩合制备甲基丙烯醛是煤基合成气(C2)路线清洁生产甲基丙烯酸甲酯的关键步骤。现有催化剂存在效率低、腐蚀性强及无法重复使用等问题，开发新型高效催化剂和反应过程机理研究是推动甲基丙烯酸甲酯技术进步及羟醛缩合绿色反应过程推广应用的关键和迫切需求。本研究将通过调变阴离子种类、基团和阳离子链长结构，合成兼具酸性与碱性的双功能离子液催化剂，获得离子液体酸碱度的调变规律；并进行以甲醛与丙醛的羟醛缩合反应为实例的过程研究，调控离子液体的酸碱度及结构特性，获得高活性离子液体催化剂；并结合原位在线检测手段辅助以分子模拟，系统地研究双功能离子液体催化剂催化羟醛缩合反应过程中α-H活化机制与反应过程机理，为通过羟醛缩合高效、绿色合成甲基丙烯醛及甲基丙烯酸甲酯清洁技术开发解决关键技术理论基础，同时为羟醛缩合反应催化剂的改进和应用推广提供理论指导。

甲醛与丙醛羟醛缩合制备甲基丙烯醛是煤基合成气(C2)路线清洁生产甲基丙烯酸甲酯的关键步骤。现有催化剂存在效率低、腐蚀性强及无法重复使用等问题，开发新型高效催化剂和反应过程机理研究是推动甲基丙烯酸甲酯技术进步及羟醛缩合绿色反应过程推广应用的关键和迫切需求。本研究通过调变阴离子种类、基团和阳离子结构，合成兼具酸性与碱性的双功能离子液催化剂。获得离子液体氢键碱性的调变规律；并进行以甲醛与丙醛的羟醛缩合反应为实例的过程研究，调控离子液体的结构特性，获得高活性离子液体催化剂二乙胺乙酸盐，转化率达到99%，选择性达到95%；并结合原位红外在线及质谱检测手段，系统地研究双功能离子液体催化剂催化羟醛缩合反应过程中反应过程机理，获得了反应过程中原子（包括α-H）流向图及中间体形式。为通过羟醛缩合高效、绿色合成甲基丙烯醛及甲基丙烯酸甲酯清洁技术开发提供关键技术理论基础。