PFSA多孔催化纳米纤维功能膜的可控制备及强化酯化反应过程

Controlled synthesis of PFSA porous catalytic nanofibers with tailored structures and morphologies for targeted catalytic performance is one of the main topics in current catalytic nanofiber research. In this proposal, a new method combining in-situ polymerization and electrospinning is proposed to prepare porous catalytic nanofibers with tailored structures and morphologies by controlling the structure of the porous nanofiber. The influences of operating conditions of in-situ polymerization and electrospinning on the structures and morphologies of PFSA porous catalytic nanofibers and PFSA molecular aggregation state will be studied by combining phase separation mechanisms and experiments. The PFSA porous catalytic nanofibers will be used for direct esterification of acetic acid and ethanol and its activity will be evaluated. Catalysis and pervaporation difunctional membrane will be prepared by effectively loading PFSA porous catalytic nanofibers on the outside surface of pervaporation membrane and used to strengthen direct esterification of acetic acid and ethanol by combing catalytic reaction and dehydration together. The microstructures of difunctional membrane and the macro-properties such as separation, catalysis and stability will be evaluated to understand the structure-performance relationship. Dynamics and thermodynamics models will be established to understand the kinetic behaviors of difunctional membrane with different structures and morphologies. The method combining in-situ polymerization and electrospinning proposed for porous catalytic nanofiber and the approaches used to understand the structure-performance relationship can also be extended to other solid acid catalysts whose active site were embedded.

多孔催化纳米纤维的可控制备及其形貌效应是当前催化纳米纤维研究领域的热点课题之一。本申请提出采用原位聚合和静电纺丝相结合的方法调控多孔纳米纤维的结构制备具有形貌和组成可控的PFSA多孔催化纳米纤维的新思路。结合相分离机理研究和实验研究，建立反应条件与多孔纳米纤维结构形态及PFSA分子聚集状态的对应关系，以实现PFSA多孔催化纳米纤维的可控制备。以乙酸乙醇直接酯化反应为模型反应体系，研究特定结构和聚集状态的PFSA多孔催化纳米纤维的催化性能，建立其构-效关系。有效地将PFSA多孔催化纳米纤维负载到渗透汽化膜外表面制备催化与渗透汽化双功能膜，并用于强化乙酸乙醇直接酯化反应过程，在催化酯化反应的同时在线脱除产物水，考察双功能膜微观形貌和宏观性能的构-效关系，并对该强化过程进行动力学、热力学建模研究，阐明双功能膜微观结构对其动力学行为的影响机制。上述调控方法也适用于许多活性中心被包埋的固体酸催化剂。

本项目针对全氟磺酸（PFSA）比表面积小的缺点，设计制备PFSA纳米纤维，从分子水平对其结构和分布进行调控，解决纳米结构催化剂颗粒易团聚等问题，提高其分散性和利用率，同时也可发挥聚合物载体的柔韧性和易操作性，以及催化材料和聚合物微纳米尺寸的表面复合产生较强的协同效应等，提高催化效能。其次，通过多喷头纺丝和改变收集器等将PFSA纳米纤维纺制在中空纤维膜上，从而制备含PFSA纳米纤维催化层、NaA分子筛分离层或聚乙烯醇分离层的中空纤维催化-渗透汽化(双功能)陶瓷膜；再将此双功能膜应用于乙酸和乙醇的酯化反应过程，在反应的同时在线脱除产物水，打破其共沸平衡，提高有机物与水的分离效率和酯的产率，降低能耗，节约成本，为后续工业化生产提供实验和理论判据，同时为新型高效催化剂的制备和工业化应用提供理论依据。..该项目已发表标注受本项目资助的论文18篇，其中SCI期刊论文13篇，EI期刊论文3篇，中文核心2篇；参与专著出版1册（《膜技术新进展与工程应用》）。已申请中国发明专利2项（均已授权），美国发明专利1项。多次参加国内国际会议，并做邀请报告2次。获得香江学者、博士后基金等人才计划和基金项目资助。