化学修饰电极的研究XVIII,四苯基钴卟啉化学修饰玻碳电极的热处理及其对氧的催化还原

本文研究四苯基钴卟啉化学修饰玻碳电极的热处理,经热处理的这种电极[(PCo/GC)h]具有对氧催化还原的异常高的稳定性和活性.在纯O2饱和的0.05mol.L^-^1H2SO4溶液中经循环伏安(CV)扫描3000次(100mV/s),其催化活性未见明显降低.研究了热处理温度(500-1000℃)对(PCo/GC)h电极电催化性能的影响.用紫外可见光谱对热处理产物的结构进行了分析.用CV法及旋转圆盘电极研究了O2在(PCo/GC)h电极上电催化反应动力学,测定了速率常数.在该电极上O2的还原反应为二电子还原成H2O2的不可逆过程.

Researches on chemically modified electrode XVIII. Heat treatment of cobalt tetraphenylporphyrin modified electrode and catalytic reduction of dioxygen on its surface

The heat treatment of Co tetraphenylporphyrin chem. modified glassy C electrode was described. The modified electrode by heat treatment [(PCo/GO)h] shows a considerable catalytic activity and stability for O reduction The catalytic activity is still maintained after 3000 circles of cyclic voltammetric scans (100 meV/s) in O saturated 0.05 mol/L H2SO4. The effects of heat treatment temperature from 500 to 1000?on the preparation and catalytic activity of the modified electrode were studied. Using UV-visible spectroscopy the possible structure of products by heat treatment on electrode surface were analyzed. The electrocatalytic and dynamic behaviors for reduction of O at the electrode were investigated by cyclic voltammetry and by rotating disk electrode resp. The rate constant of O reduction at (PCo/GC)h electrode in 0.05 mol/L H2SO4 was measured. The catalytic reduction of O to H2O2 at the electrode is a 2-electron irreversible process.