对甲基苯磺酸在Ti/PbO_(2)电极上的电氧化反应信息

Electro-oxidation information of p-toluene sulfonic acid on Ti/PbO_(2) electrode

采用原位红外光谱法系统地研究了对甲基苯磺酸(p-TSA)在钛基二氧化铅(Ti/PbO_(2))电极上的电氧化反应信息。循环伏安曲线显示,Ti/PbO_(2)对p-TSA有良好的电氧化活性,直接氧化电位区间为0.55~0.9 V。多步电位阶跃FTIRS(MSFTIRS)和时间分辨FTIRS(TRFTIRS)分析显示,电压小于1000 mV时,p-TSA主要发生了磺酸基的脱落和苯环侧链甲基的氧化;电压大于1000 mV时,p-TSA的苯环骨架被破坏,同时生成了酸、醇、酮。反应动力学研究结果表明,p-TSA电氧化表观速率常数K与电流密度j呈线性关系,化学需氧量(COD)去除量随比电荷增大而增加,平均电流效率则呈下降趋势。

In situ infrared spectroscopy was used to systematically study the electro-oxidation reaction information of p-toluenesulfonic acid(p-TSA)on the titanium-based lead dioxide(Ti/PbO_(2))electrode.The results of cyclic voltammentry curve indicated that Ti/PbO_(2) electrode exhibited a high electrochemical activity for the oxidation of p-TSA,and the direct oxidation potential ranged from 0.55—0.9 V.When the voltage was less than 1000 mV(vs.SCE),the multi-step potential FTIRS(MSFTIRS)and time-resolved FTIRS(TRFTIRS)analysis showed that the p-TSA was in the process of breaking of sulfonic acid group and methyl group oxidation of side-chain of benzene ring.When the voltage was higher than 1000 mV(vs.SCE),the aromatic ring of p-TSA was degradated.Meanwhile,the compounds of acid,alcohol and ketone were generated.The results of the reaction kinetics study showed that the apparent rate constant K of p-TSA electrooxidation has a linear relationship with the current density j,the removal of chemical oxygen demand(COD)increased with the increase of specific charge,and the average current efficiency showed a downward trend.