基于限域催化的空腔微反应器及其对高风险痕量有机物降解路径调控的作用机制

To efficiently remove the high-risk micropollutants from aquatic environment, it is of critical importance to enhance the selectivity of photocatalytic process. This project dedicates to the design and synthesis of macrocyclic supramolecular microreactor and its enhanced removal mechanisms for organic micropollutants via selective photocatalytic oxidation. To resolve the technical problems in traditional photocatalytic oxidation process, including low selectivity toward target pollutants and possible generation of toxic intermediate products, this project proposes to synthesize microreactor through artificial modification of the macrocyclic supramolecules or changing the distribution of functional groups, for the purposes of facilitating micropollutants mineralization and directing the degradation pathway toward less toxic byproducts formation. The cavities provided by host supramolecules like cyclodextrins are expected to act as reaction vessels to trap micropollutants, as well as to facilitate their degradation by regulating electron transfer and energy distribution. By this method, in situ and controllable degradation of the pollutants at “reactive sites” can be achieved. The enhanced removal mechanisms of pollutants confined within the cavities, the interface reaction mechanisms, and the relationship between pollutant removal efficiency and reactor structure will be elucidated using various analytical and characterization method, and the mechanism of action of confinement on pollutants, degradation process and degradation products will be revealed. By studying the application of confined photocatalysis for advanced water purification, this project is expected to offer new concepts and technical supports for efficient removal of refractory micropollutants from aquatic environment.

提高光催化的选择性对水中高风险痕量有机物的去除至关重要。本项目拟构筑一系列具有限域催化效应的大环空腔微反应器，研究其对高风险痕量有机物的光催化降解机制。针对传统光催化选择性弱、中间产物风险高等问题，从反应器设计出发，通过人工修饰调控空腔及催化剂分布，基于限域效应、利用不同的空腔结构控制痕量污染物降解路径，使其在空腔内按低毒性降解路径进行脱毒矿化；调控体系电子转移和能量分布，充分发挥环糊精等限域空腔的“活性中心”作用，使其既作为污染物识别区，又作为限域催化反应区，实现污染物的可控降解；结合原位表征和量子化学理论计算，解析限域空腔与污染物降解效率间的构-效关系，探明微反应器去除目标污染物的表界面特性，揭示限域空腔对污染物、降解过程和降解产物三个层次上的调控作用机制；通过探索限域光催化过程在污水深度处理中的应用，为难降解有机微污染物的高效去除提供新思路和技术支撑。

本项目针对水中高风险痕量有机物去除的难题，开发了一系列基于限域催化效应的大环空腔微反应器，并探究其对水中目标污染物的富集与降解效能。首先基于环糊精大环配体独特的空腔结构和“外亲水，内疏水”的特性，构建特异性识别吸附材料，充分发挥环糊精等限域空腔的“活性中心”作用，使其既作为污染物识别区，又作为催化反应区，实现污染物的吸附与降解；耦合生物质材料、二氧化钛等材料，构筑一系列选择性催化氧化的空腔微结构，以提升污染物的去除能力；研究了不同污染物的光催化降解路径，解析限域空腔与污染物降解效率间的构-效关系，探明微反应器去除目标污染物的表界面特性，揭示限域空腔对污染物、降解过程和降解产物三个层次上的作用机制，为难降解有机微污染物的高效去除提供新思路和技术支撑。在本项目的资助下共发表学术论文27篇，所发表的期刊中既有Journal of Hazardous Materials, Chemical Engineering Journal, Chemosphere等国外SCI期刊，也有中国化学快报（CCL）和环境科学学报等高水平中国期刊。同时申请国家发明专利4项；培养了7名硕士研究生（均已获得硕士学位）。