Ti/IrO2+MnO2电极在酸性溶液中的析氧反应动力学研究

Kinetics of oxygen evolution reaction on Ti/IrO2+MnO2 electrodeform acid solution

摘要:

采用涂覆热分解法制备Ti/IrO₂+MnO₂复合电极,利用慢速线性电位扫描伏安法测试Ti/IrO₂+MnO₂电极的准稳态极化曲线并深入地研究析氧反应动力学,得到了相关动力学参数、反应历程及速度控制步骤。通过分析经欧姆电压降修正的Tafel曲线,较好地解释了Tafel直线区域的双斜率现象,基于此提出析氧反应动力学方程并进行数学推导,较好地符合实验结果。实验所得氢离子反应级数约为零,低电位区与高电位区的表观活化能分别为30.31kJ/mol和13.64kJ/mol,进一步证明该数学模型的正确性。

Abstract:

Ti/IrO2+MnO2 composite electrodes were prepared by thermal decomposition. The kinetics of oxygen evolution reaction on Ti/IrO2+ MnO2 electrodes were studied deeply with quasi-stationary polarization curve recorded by slow linear potential sweep voltammetry. The related kinetics parameters, reaction process and rate determining steps were obtained. Tafel linear regions wih double slopes were explained well by analyzing the ohmic voltage drop corrected Tafel curves. Kinetics equations based on the proposed oxygen evolution reaction mechanism were deduced mathematically, which were in good agreement with the experimental results. The reaction order of hydrogen ion close to 0, the one of apparent activation energy of 30.31kJ/mol in the low potential region and the other of 13.64kJ/mol in the high potential region, further proved the correctness of above mathematical model.