磁性复合粒子固体酸Pickering界面催化剂的制备及催化两相反应研究

To resolve the problems (such as low catalytic efficiency, difficulty in separation and recovery of catalysts, and deactivation of catalysts, etc.) existed in solid acid catalyzed biphasic reaction for preparing biodiesel, amphiphilic magnetic composite solid acid containing multi-level active sites will be designed and prepared in this project, which will be used as Pickering interface catalyst for efficient catalytic application in biphasic reaction. The influencing factors of the structure and properties of the magnetic composite solid acid will be systematically studied, and the morphology and wettability of the composites will be regulated, so as to improve the stability of the Pickering emulsion. The structure–effect relationship between the composition and distribution of active sites of the magnetic composite solid acid, the microstructure of Pickering emulsion and catalytic performance will be clearly defined. Combined with the study of reaction kinetics, reaction path, product composition and selectivity, the mechanism of Pickering emulsion interfacial synergistic catalysis will be elucidated. The research results of this project will not only provide a theoretical basis for the design and controllable preparation of Pickering interface catalysts with high activity, high stability and easy separation and recovery, but also have practical guiding significance for preparation of new chemical products by efficient biphasic reactions.

针对固体酸催化两相反应制备生物柴油的效率低、分离回收难及易失活等问题，本项目拟设计制备含有多级活性位点的两亲性磁性复合粒子固体酸，将其作为Pickering界面催化剂，实现其在两相反应中的高效催化利用。通过系统研究磁性复合粒子固体酸结构性能的影响因素，调控其结构形貌和润湿性能等，提高Pickering乳液的稳定性。明确磁性复合粒子固体酸的活性位点组成分布和Pickering乳液的微观结构与催化性能的构效关系；并结合反应动力学、反应路径、产物组成和选择性研究，阐明Pickering乳液界面协同催化机理。本项目的研究成果不仅为高活性、高稳定性、易分离回收的Pickering界面催化剂的设计和可控制备提供理论依据，而且对于实现两相反应高效制备生物柴油等新型化工产品也具有实际指导意义。

针对固体酸催化生物质和废油脂转化两相反应效率低、分离回收困难等问题，本项目通过回流沉淀聚合制备聚合物微球，再经过接枝、磺化等对其进行表面修饰，分别制备了磺化聚苯乙烯（磁性）微球、含磺酸基和烷基链的两亲性聚合物（磁性）微球固体酸。还通过一步无皂乳液聚合制备含磺酸基聚合物微球。探讨了功能单体用量、交联单体用量、反应介质等因素对固体酸微球结构性能的影响规律，获得了聚合物微球固体酸的可控制备方法。系统研究两亲性聚合物微球固体酸结构性能的影响因素，通过调控其结构形貌和润湿性能，提高Pickering乳液的稳定性，并调节其尺寸和形貌。当烷基链长为12时，所得两亲性聚合物微球固体酸C12-PS-SO3H的酸密度为1.20 mmol/g、水接触角为59.4o，显示较强的酸性和较好的两亲性；可以分散两相体系形成稳定的Pickering乳液，应用于催化油酸/甲醇酯化、月桂酸/正丁醇酯化、果糖脱水显示较高的催化活性。系统研究了原料配比、催化剂用量等因素对Pickering乳液及催化效率的影响，获得了最佳配方和工艺条件；详细研究了Pickering界面催化反应动力学，阐明了两亲性聚合物微球固体酸的结构性质与催化性能的构效关系，揭示了Pickering界面增强催化效率的机理。该研究成果不仅为高活性、高稳定性、易分离回收的Pickering界面催化剂的设计和可控制备提供理论依据，而且对于实现两相反应高效制备生物燃料和平台化合物也具有实际指导意义。