铂修饰电极催化氧化苯酚的热力学研究

THE THERMODYNAMICS STUDY OF ELECTROCHEMICAL OXIDATION OF PHENOL ON PLATINUM MODIFIED GLASSY CARBON ELECTRODE

研究苯酚在铂修饰玻碳电极上的电化学氧化.考察了温度、pH值和苯酚浓度对苯酚电化学氧化的影响.结果表明,随着温度的升高,苯酚的氧化峰电位逐渐减小,氧化峰电流逐渐增大;随着pH值的增大,氧化峰电位逐渐减小,峰电流开始逐渐减小,在pH7.5时突然增大,然后又减小;随着苯酚浓度的增大,苯酚的氧化峰电位逐渐减小,峰电流增大.苯酚在铂修饰电极上的电化学氧化反应活化能为14.6kJ·mol-1.

The electrochemical oxidation of phenol on platinum modified glassy carbon electrode has been investigated. Various influence factors such as temperature, the pH value of electrolyte and the concentration of phenol were examined. The results indicated that the peak potentials shift more negative values when temperature, pH value and the concentration of phenol increased. The peak current increases with temperature and the concentration of phenol. However, the peak current decreased with the increased pH valve between 3 and 7; the peak current increase obviously at pH 7.5, and then decrease following the increased pH value. Activation energy which was obtained from the experimental data, was 14. 6kJ·mol^-1. The thermodynamics analyses show that polymerization process takes place without any side reaction at 187K. And after 375K the main reaction tends to be the degradation of phenol and the polymer film performed in the surface and this reaction is spontaneous.