金属卟啉、酞菁修饰钛电极的研究(Ⅳ)——金属卟啉、钛菁修饰钛电极的频率响应分析

来源期刊：中南大学学报(自然科学版)1986年第1期

论文作者：裘晓滨 宋诗哲 赵天从

文章页码：101 - 109

关键词：金属卟啉； 金属酞菁； 修饰电极； 氧析出； 电催化； 交流阻抗； 频率响应

Key words：metalloporphyrines； metallophthalocyanins； modified electrode； oxygen evolution； electrocatalysis； impedance； frequency response.

摘    要：本文采用交流阻抗技术,测定了聚酞菁铁、四对氯苯基卟啉镍修饰酞电极的频率响虚特性。频谱图表明电极过程由电荷传递所控制。提出电极过程的电化学等效电路,出计算机曲线拟合求得电荷传递电阻、有效界面电容等电化学参数,进而求出氧析出反应的交换电流和塔菲尔常数。结果表明氧在这种电极上的析出反应主要是一个二电子过程。反应过程中随着电位的变化,氧析出反应的速度控制步骤发生变化。这与稳态极化曲线所观察到的现象是一致的。

Abstract: This research work involved determining by means of the impedance technique the frequency response character of electrodes modified with iron poly-phthalocynine and nickel-tetrakis (para-chloro-phenyl) porphyrin. Frequency spectra denote that the electrode process is charge transition controlled. In this paper an electrochemical equivalent circuit was suggested and, based on obtainment of electrochemical parameters such as charge transition resistance and effective interface capacity by the computer curve-fitting methods, the magnitude of exchange current and the Tafel constant for O₂ evolution were attained. The results indicated that O₂ evolution on such electrodes is mainly a 2-electron process. It was found that, with potential changing during the reaction, there would be variation in the O₂ evolution rate controlling step, which was in good agreement with results obtained in the case of the use of anodic polarization curves.