Ru-Ir-Ti氧化物阳极正反电流电解失效机理研究

应用热分解法制备适用于海水电解的钛基金属氧化物阳极.由SEM、EDX和XRD分析表征该阳极的形貌、成分及相结构,结果表明,烧结后阳极表面形成了固溶体结构,分别为(Ru,Ir,Ti)O2和(Ir,Ti)O2,失效后氧化物阳极的固溶体结构几乎完全消失,活性物质丧失.强化正反向电流寿命测试、循环伏安曲线和电化学阻抗谱等测试表明,失效后氧化物阳极表面的电化学活性点大大减少,同时膜电阻增加,这是由于活性物质脱落导致的,进一步说明正反向电流导致阳极表面活性物质脱落是氧化物阳极失效的根本原因.

The Deactivation Mechanism of Metal Oxide Anodes under Alternative Current Electrolysis Condition

The metal oxide anodes coated on titanium used in seawater electrolysis were prepared by thermal decomposition.Their morphologies、compositions and phase structures were determined by scanning electron microscope(SEM)、energy dispersive X-ray detector(EDX) and X-ray diffraction(XRD).The electrochemical properties of the anodes were characterized by accelerated life test,cyclic voltammetry and electrochemical impedance spectroscopy.SEM、EDX and XRD showed that solid solution structures of(Ru,Ir,Ti)O_(2)and(Ir,Ti)O_(2) were formed after pyrolysis,the solid solution structures and active components were disappeared after the deactivation of the anodes.Electrochemical results indicated that the active area decreased and the coating resistance increased,which are resulted by active component falling off from the anode surfaces.Hence,the deactivation of the oxide anodes was due to detachment of the active component under alternative current electrolysis.