P、N双配体胶囊钯催化剂的可控制备及其在调聚反应中的应用研究

Telomerization of butadiene with carbon dioxide has attracted extensive attention for which has multiply significance on saving fossil resource, reducing greenhouse gas emission and balancing between supply and demand on butadiene. Moreover, the product of δ-lactone is a highly potential versatile platform chemical. For enhancing the catalytic activity and selectivity of this conversion process, we propose a new strategy that establishes a catalyst carrier with the coordination of organic amine and phosphine ligand to activate carbon dioxide and modulate the selectivity and stability of palladium. In the project, we focus on the controllable preparation of palladium catalyst immobilized on microcapsule with dual-ligand based on microfluidic technology and layer-by-layer adsorption to realize this strategy. Therein, we attempts to: (1) elucidate the fundamental on organic amine adsorption and palladium coordination in thermodynamics and kinetics; (2) understand the coordination mechanism and modulation method for microenvironment affected by dual-ligand; (3) evaluate the catalytic performance of the new immobilized palladium catalyst on telomerization of butadiene with carbon dioxide and explore the key points for reaction process intensification; and (4) establish reaction kinetics model and consolidate the foundation for new telomerization process without solvent. Aforementioned investigation is prominently meaningful with the respect of academic and application, since it will promote to disclose the characteristics of telomerization, enrich the theory and technology for versatile complex microcapsule preparation, develop carbon dioxide catalytic conversion process with industrial perspective, and realize resource utilization of carbon dioxide and butadiene.

二氧化碳和丁二烯之间的调聚反应具有节省化石资源、减排温室气体、平衡丁二烯供需的多重意义，产物δ-内酯是一种有潜力的多功能平台化合物。本课题在剖析该过程催化活性和选择性制约因素的基础上，提出构建有机胺与高分子固载膦配体协同进行二氧化碳活化和钯选择性及稳定性调控的载体与负载催化剂设计机制，发展基于微流控技术与逐层吸附的双配体钯负载微胶囊的可控制备方法，阐明其中涉及的吸附和配位过程的热力学与动力学基础问题，认识双配体微环境的协同机制和调控方法，评估双配体钯负载微胶囊对二氧化碳和丁二烯调聚反应的催化性能并探究强化该过程的切入点，建立反应动力学模型，为开发无溶剂条件下的高效新工艺提供基础。上述研究对于认识调聚反应的基本规律，丰富多功能复合微胶囊制备的理论和技术，实现具有工业应用前景的二氧化碳催化转化过程，解决二氧化碳和丁二烯的资源化问题都将起到非常重要的推进作用，兼具重要的学术意义和应用价值。

二氧化碳是自然界中最大的碳资源，利用1,3-丁二烯实现其化学转化，具有节能减排、化石资源利用以及平衡丁二烯供需失衡问题具有重要的研究意义。本项目研究并构建了三种可控制备胶囊钯催化剂的微型化平台，并利用有机磷单体和PEI改性法，引入N,P双功能配体，实现了对 Pd(0) 配位，制备了具有吸附活化 CO2 和催化转化功能的双功能催化剂；催化剂尺寸可实现几十到几百微米的调控机制，内部结构可通过改变分散相溶剂环境实现由致密到疏松多级孔结构的调节规律；在1,3-丁二烯和CO2的催化转化过程中，1,3-丁二烯的转化率可高达97.7%，生成内酯的选择性高达98.6%，该结果明显优于文献报道结果，转化率高出近40%，选择性高出35%左右；原位红外进一步验证了催化反应机理过程，并探明酯羰基伸缩振动峰的吸光度随反应时间延长呈线性增长的动态变化趋势。