硫酸溶液中苯酚在Ti/PbO_2电极上的循环伏安研究

A Cyclic Voltammetric Study of Phenol on Ti/PbO_2 Electrode in H_2SO_4 Solution

用循环伏安法研究了Ti/PbO2电极在苯酚硫酸溶液中的电催化作用.结果表明,在硫酸溶液中,Ti/PbO2阳极对苯酚具有电催化氧化作用.如果苯酚浓度较低,产生的吸附态羟基自由基可以将苯酚氧化,直至完全矿化.当苯酚浓度较高或产生的羟基自由基量相对较小时,苯酚或中间产物可吸附在电极表面,降低电极的真实表面积,减少电极的活性点,阻止反应物接近电极表面,抑制苯酚的进一步氧化.随着电解时间的延长,这些吸附物由于逐渐被氧化,电极活性恢复.

The electrocatalytic performance of Ti/PbO2 electrode was investigated during the electrochemical oxidation of phenol in H2SO4 solution by cyclic voltammetry. The results have shown that Ti/PbO2 electrode have strong oxidation properties for phenol in H2SO4 solution. In a low initial concentration of phenol, phenol can be oxidized by adsorbed hydroxy radicals generated on electrode and finally mineralized. In a higher concentration phenol or little adsorbed hydroxy radicals generated, phenol and its intermediates may be adhesive to the electrode surface, consequently diminishes the electrochemical active surface area of electrode leading to the decrease of active sites, prevents the reactants from approaching the electrode surface and inhibits the further oxidation of phenol. With the increase of electrolysis time, the electrode activity can be restored due to the gradual oxidation of the substances adsorbed on electrode surface.