三维碳材料复合电极电催化降解有机工业废水的原位光谱电化学研究

Organic pollutants are typical toxic and refractory contaminations present in industrial wastewater, which can be treated by electrocatalytic degradation as one of the green and efficient new methods. During the catalysis research in electric drive technology, it is a crucial to develop novel electrode materials and gain a deeper understanding on the mechanism of electrocatalytic oxidation and degradation. This is conventionally studied using ex-situ methods, but they have limitations for unstable intermediates and surface adsorbents. Based on our preliminary work, we will prepare novel three dimensional carbon-based composite materials as the electrode, then establish an in-situ ATR-FTIR spectroelectrochemistry platform based on conductive transparent diamond electrode. With this platform, the adsorption of reactants and intermediates on the electrode produced during the electrocatalytic process can be studied in-situ, by acquiring in-situ infrared spectra during electrocatalytic process. This study will reveal the relationship between the formation of passivation layer, the rate limiting step and the property of electrode materials, and reveal the electro-catalytic degradation mechanism of pollutants on three dimensional carbon-based composite electrodes and provide guidance for the fabrication of high performance electrode materials.

有机工业废水中含有大量高毒性、难降解的有机污染物，电催化降解是处理这类废水的一种绿色高效的新方法；在电催化技术研究的程中，新型电极材料的制备及其对有机工业废水的电催化机理和降解机理是该研究方向的关键性科学问题之一。电催化机理研究中传统的异位检测方法很难测到不稳定的中间产物和表面的吸附状态，具有一定的局限性。本项目将在申请人前期工作基础上，制备新型的三维碳材料复合电极，在基于导电金刚石透明电极的衰减全反射红外光谱电化学平台上,原位研究电催化过程中反应物在电极表面的吸附过程、催化中间产物和动力学，揭示聚合物钝化层形成和电催化限速环节与电极材料性质的规律，得到三维碳材料复合电极的电催化机理和污染物降解机理，为优化设计高效、稳定的新型电极催化材料提供理论支撑。

有机工业废水中含有大量高毒性、难降解的有机污染物，电催化降解是处理这类废水的一种绿色高效的方法；在电催化技术研究中，新型高效电极材料的制备及其电催化降解有机工业废水的机理，是该研究方向的关键性科学问题之一。电催化机理研究中，传统的异位检测方法很难测到不稳定的中间产物和表面的吸附状态，具有一定的局限性。基于此，本研究采用衰减全反射傅里叶红外（ATR-FTIR）光谱技术，与电化学技术进行联用，搭建了原位实时检测平台，用于深入解析不同电极上有机污染物的催化机理。研究不同材料三维电极和导电金刚石（BDD）电极对苯酚的电催化降解历程，并借助原位红外光谱电化学平台，探讨中间产物的在电极表面的吸附富集过程及降解机理。研究表明:（1）相比于Ti基形稳电极Ti/SnO2-Sb/PbO2，新制备的CF/PbO2电极在苯酚的降解过程中的电催化速率常数提高了11倍，能耗降低了5-9倍；（2）制备的基于两种不同孔径钛毡的三维二氧化锡负载电极，在本项目设计的固定床连续流反应器中对苯酚均有良好的降解性能，苯酚在两种钛基三维电极上的降解过程符合一级动力学方程，在细孔钛毡/SnO2-Sb电极上动力学常数为0.025min-1，是大孔钛毡/SnO2-Sb电极动力学常数的1.67倍，表明细孔钛毡/SnO2-Sb电极具备更强的电化学降解性能，同时在三维粒子电极实验中发现活化有序的电极表现出更好的降解性能；（3）原位红外电化学光谱平台能够实时表征苯酚的电催化降解历程，尤其是检测电极表面直接电子转移产生的降解中间产物，比如在BDD和三维二氧化铅电极表面能够检测到非原位检测手段鲜有报道的间苯二酚中间产物的产生。