低电位感应电还原-催化加氢协同的典型卤代PPCPs电化学脱毒机理研究

Electrochemical reduction is an effective technology for the removal of halogenated contaminants, however, the high negative cathode potential and low mass transfer are two main problems. The efficient generation and utilization of active atomic H* is the key to improving the treatment efficiency and lowering the energy cost. In this project, a combined process of electrochemical reduction, induced electrochemical reduction, and catalytic hydrogenation will be developed for the efficient detoxification of typical halogenated pharmaceuticals and personal care products (PPCPs), such as diclofenac and triclosan. The main objectives of this project are the effective production and regulation of atomic H* at a low negative potential and the selective dehalogenation of contaminants, by strengthening the electron transfer rate and mass transfer efficiency in the coupled reduction process. A Pd/heteroatom doped graphene electrode is fabricated and used as the cathode, and Pd@ordered mesoporous carbon particles are used as the induced electrodes in the cathode cell. The physical and chemical structures of the electrodes, the production of atomic H* at the electrodes surface, and their catalytic activities will be associated. The property of the cathode to adsorb atomic H* and the underlying mechanism will also be investigated. For the coupled reduction system, the critical factors, synergetic mechanism, and electrochemical regulation method will be illuminated on the basis of analysis of the role of atomic H*. Finally, the reaction mechanism for the degradation of halogenated PPCPs in the synergistic process will be proposed. The results of this project will enable the detoxification of halogenated PPCPs, and provide theoretical support for the improvement in effciencies of electrochemical reductive water treatments and their applications.

电化学还原是一种去除卤代污染物的有效方法，但也存在阴极所需负电位高、传质效率差的问题。如何有效产生与利用原子H*等活性物种是提高效率与降低能耗的关键。本研究围绕上述关键问题，以三氯生、双氯芬酸等典型卤代药品和个人护理品（PPCPs）的高效脱毒为目标，通过构造电化学/感应电化学/化学还原多过程耦合的水处理微场，建立原子H*高效产生与利用的催化脱卤体系，强化电子转移及传质，实现低电位下原子H*的有效调控及污染物去除。以Pd/三维杂原子掺杂石墨烯电极作为主阴极，Pd@有序介孔碳作为感应粒子电极，解析电极微观结构与产H*能力和催化活性之间的构效关系，从分子水平研究阴极优势结构固氢机制。深入研究多过程耦合体系原子H*产生及作用机制，明确关键因子、耦合机制及电化学调控方法，揭示卤代PPCPs的微观反应机理。本项目研究可为卤代PPCPs脱毒提供解决途径，为电还原水处理技术效率提升与工程应用提供理论依据。

电化学还原是一种去除卤代药品和个人护理品（PPCPs）的有效方法，其通过电子或原子H*还原作用选择性去除卤素原子。目前电还原法存在阴极所需负电位高、传质效率差、关键还原物种原子H*产生及利用效率低等问题。本项目针对上述科学问题，以泛影酸钠、三氯生等典型卤代PPCPs的高效去除为目标，研制出具有电子耦合和优异固氢特性的Pd/氮掺石墨烯复合电极和Pd/有序介孔碳粒子电极等电极，与常规Pd基电极相比明显降低了其阴极电还原电位，揭示了Pd与石墨烯通过电子耦合作用强化产原子H*原理；构建电化学/感应电化学/化学还原多过程耦合的催化反应体系，通过耦合体系关键因子识别及电化学调控，实现低电位下对原子H*的有效调控及污染物去除。.主要创新点包括：利用电极-水界面原子H*表征方法深入研究不同催化电极界面产H*规律，揭示Pd/氮掺石墨烯耦合电极强化原子H*产生及作用机制；制备了高活性Pd/OMC感应粒子电极，构建电化学/感应电化学/化学还原多过程耦合催化反应体系，实现低电位下原子H*高效产生及利用与多过程协同去除卤代有机物。本项目研究成果可为卤代PPCPs废水有效处理提供科学依据，为发展高效、节能的电化学水处理技术提供新的思路。