不对称磺酸卟啉-超支化聚合物复合催化体系的制备及其对多卤代酚的高效催化降解性能

Polyhalogenated phenols have important industrial application. They have also been toxic, persistent and regarded as priority pollutants for the environment. The dehalogenation degradation by the sulfoporphyrins has been studied over the last years. Due to the synthesis and purification difficulty of these porphyrins, very few literatures can be found about the synthesis and the corresponding catalysis of the asymmetric sulfoporphyrins. In this research, a new series of asymmetric sulfoporphyrins will be synthesized. Together with the amphiphilic hyperbranched multi-arm copolymers, they will be used as a new kind biomimetic P450 enzyme system. This new complex catalytic system can efficiently catalyze the polyhalogenated phenols through dehalogenation degradation under mild conditions. The effect of the numbers and linked positions of the sulfonic substituents on the catalytic mechanism, catalytic active center structure and the steric conformation of porphyrin/copolymer complex systems will be investigated in detail. Trying to provide a new way to serve the main drawbacks for current calysts for the degradation of polyhalogenated phenol: 1) expensive preparation for the catalyst; 2) difficult recycled use of the catalyst; 3) lower catalytic activity and catalytic stability. The research content will include following aspects: 1) the synthesis and characterization of new series of asymmetric sulfoporphyrins, in which the sulfonic substituents will be placed in different positions in the phenyl groups of the porphyrins; 2) preparation of amphiphilic hyperbranched multi-arm copolymers whose core cavity and shell arm length will have different size; 3) the preparation of the porphyrin-copolymer catalytic systems and their catlytic degradation of the polyhalogenated phenols; 4) the examination of the performance of the catalytic systems; 5) the quantum calculation of the steric conformation of porphyrin-copolymer catalytic systems, the investigation of the catalytic mechanism and the catalytic active center. This research will be great useful for searching and investigating the efficient recycled biomimetic catalysts and for the development and the commercialization for dehalogenation degradation of polyhalogenated phenols in wastewater and environmental restoration.

多卤代酚具有重要的工业应用，也是具有强环境毒性的难降解、持久性的有机污染物，对人类及生态环境造成严重威胁。磺酸基卟啉对该类污染物的催化降解作用近年来引起了广泛关注。但由于合成及纯化的高难度，几乎未见不对称磺酸卟啉的合成及催化报导。本项目拟合成系列新型不对称磺酸卟啉，与具有不同内核空腔及臂长外壳的超支化聚合物组成复合催化体系，模拟天然P450酶催化体系，温和条件催化降解多卤代酚污染物。考察磺酸基的数目及连接位置对卟啉活性中心结构、催化活性及稳定性的影响；在保持高催化活性及稳定性的同时，利用卟啉与聚合物之间的相转移性质，筛选再分离、循环使用的卟啉-聚合物复合催化体系，降低昂贵的合成成本；量化计算催化剂活性中心构象，计算反应过渡态构型，探讨与催化活性的关系；开展反应机理和快速反应动力学研究，结合量化计算，探讨催化机理。将对寻找高效循环使用的仿生催化剂用于多卤代酚污水处理、环境修复具有重大意义。

酚类化合物，尤其是多卤代酚具有重要的工业应用，也是具有强环境毒性的难降解、持久性的有机污染物，对人类及生态环境造成严重威胁，探索高效可回收循环使用的环保仿生催化剂来催化降解废水中日益增加的酚类化合物具有重要的科学意义及潜在的应用价值。本项目合成了一系列的高纯度的水溶性不对称磺酸卟啉，以及具有不同内核空腔及臂长外壳的系列超支化聚合物，探究了二者间的主客体化学行为，探索了该体系非共价相互作用，制备了卟啉/聚合物的复合物，该复合物可以在水/有机两相间形成薄膜，并作为多相催化剂成功应用于对酚类的催化氧化降解反应，获得了较高的催化活性、稳定性及循环使用效果。考察了卟啉化合物中磺酸基的数目及连接位置，以及不同分子量的超支化聚合物结构对多相催化剂中卟啉活性中心结构、催化活性及稳定性的影响；解决了均相的水溶性卟啉在催化体系中易形成惰性二聚体且易光解的难题，实现了催化剂的回收利用以及产物的分离。探讨了该类薄膜型多相催化剂的反应动力学以及催化反应机理，筛选了具有最佳催化活性、稳定性及循环使用（10次）的卟啉/聚合物多相催化剂，已申请了专利。. 在此基础上，致力于探索环保型的水溶性磺酸卟啉通过改进磺化路线成功制备了五种含不同取代基及取代位置的水溶性磺酸卟啉研究，具体为改进卟啉的磺化过程，不仅提高了产率，而且磺化剂及磺化条件更加环保。同时，探索了将水溶性磺酸卟啉负载在其它载体，如碳纳米管及石墨烯上，分别制备了高效、稳定、可循环的新型卟啉/多臂碳纳米管及卟啉/石墨烯多相催化剂，应用于双相催化氧化1,5-萘二酚、2，3-萘二酚、活性艳红X-3B等其它底物，转化率在120分钟内高达88%，可多次循环利用，有效减缓了卟啉催化剂自身易降解的难题，有望应用于工业上废水处理。同时，对两类卟啉负载催化剂的反应动力学及催化机理进行了深入研究。