钛基二氧化铅电极上氯析出过程的研究

STUDY ON THE ANODIC REACTION OF CHLORINE EVOLUTION ON Ti/β-PbO_2ELECTRODE

用极化曲线法研究了钛基二氧化铅电极(β-PbO_2)在NaCl溶液中的阳极析氯过程。结果表明,反应速度与Cl^-离子浓度成正比,H^+离子通过OH^-离子的竞争吸附对析氯过程起促进作用。电极转速对阳极极化曲线没有影响,说明扩散过程不起控制作用。稳态动力学数据指出,氯的析出机理符合电化学放电规律,速度控制步骤为:MCl^-_(adi)→MCl^-_(adi+e)。

The kinetics of the chlorine evolution reaction on Ti/β-PbO_2 electrode has been studiedbased on the current-potential curves using a rotating disc electrode. The reaction rate affect-ing factors, such as Cl^- ion concentration and pH of the solution, have been examined, thebydrogen ions were found to promote the chlorine evolution reaction. This has been ascribedto the competitive adsorption between H_2O molecules and chloride ions at the active sites ofthe electrode surface. The following parameters were determined: the anodic transfer coeffi-cient, Tafel slope, and the reaction orders with respect to Cl^- and H^+. From the experimen-tal results the rate determining step of the anodic evolotion of chlorine on Ti/β-PbO_2electrode is found to be MCl_(ads)^----MCl_(ad?)+e