聚吡咯纳米管阵列修饰Pd-Ag双金属复合电极上2,4,6-三氯酚加氢还原研究

Electrocatalytic hydrodechlorination is one of the most important routes to treat chlorinated organic compounds, due to its mild reaction conditions and high degradable ratio. Pd-MIB (Cu, Ag and Au) bimetallic electrodes exhibit superior catalytic properties in electrocatalytic hydrogenation of chlorphenols. In this project, therefore, the polypyrrole nanotube array (PPyNTAs) is used as the carrier of Pd-Ag bimetallic catalytic electrodes for the selective hydrodechlorination of 2,4,6-TCP, to benefit from its large surface area and high assistant catalytic activity. The morphology and structures of Pd-Ag active sites can be controlled and the relationship between catalyst structure and catalytic activity can be clarified through altering the preparation method and optimizing the preparation conditions; The intrinsic connections between the function of PPyNTAs, Pd-Ag synergism and catalytic activity in 2,4,6-TCP selective hydrogenation can be explored by using different synthetic PPyNTAs; The reaction mechanism can then be proposed via reaction kinetics study and in-situ characterizations. The progresses made by performing this project will promote the researches on applications of electrode modified with PPyNTAs and be of benefits to further understanding of structure-performance relations, Pd-Ag synergism and reaction mechanism for 2,4,6-TCP hydrogenation. It may also provide us some new thoughts to the design and preparation of efficient electrodes for electrocatalytic hydrogenation in nano-scale.

电催化加氢脱氯法是一种处理氯代有机物的重要方法，具有反应条件温和、降解彻底等优点。Pd-MIB（Cu、Ag和Au）双金属催化剂具有优异的氯酚电催化加氢性能。本项目拟采用高比表面和助催化活性的聚吡咯纳米管阵列(PPyNTAs)修饰Pd-Ag双金属复合电极用于2,4,6-TCP加氢还原，通过改变制备方法和优化制备条件控制Pd、Ag纳米粒子尺寸、形貌以及结构，深入研究Pd-Ag形貌、结构与催化活性之间的有机联系；合成不同性质的PPyNTAs，探究PPyNTAs载体效应、Pd-Ag协同作用及2,4,6-TCP选择性加氢还原性能之间的内在关系；通过催化反应动力学和原位表征等研究提出反应机理。本项目取得的进展将促进PPyNTAs修饰催化电极的应用研究，加深对 Pd-Ag构效关系、协同作用和2,4,6-TCP加氢还原反应机理等方面的科学认识，为从纳米尺度上设计制备新型高效电催化加氢电极提供新思路。

电催化加氢脱氯法（ECH）是一种处理氯代有机物的重要方法，具有反应条件温和、降解彻底等优点。Pd-MIB（Cu、Ag和Au）双金属催化剂具有优异的氯酚电催化加氢性能。本项目制备采用硬模板法制备了几种聚吡咯纳米阵列修饰电极，采用两步法和一步法制备出聚吡咯修饰的Pd-Ag双金属复合电极；纳米Ag立方@Pd双金属催化剂对2,4,6-TCP的脱氯速率快，表明Pd、Ag的协同效应；实验研究得出水中氯酚在Pd修饰电极上的ECH反应机制为前置活化的界面反应，符合吸附活化-氢溢流协同机制，质子化效应是酸性条件下ECH容易的发生内因；水中亚硫酸根抑制ECH反应，亚硫酸根对Pd催化剂的毒性是可逆的；制备了几种低成本高性能的金属氧化物阳极。本项目的实施可为水中卤代有机物的电催化处理提供理论依据和参考。