SPE水电解池氧电极研究

Study on oxygen electrode of SPE water electrolyzer

氧电极是固体聚合物电解质(SPE)水电解池(WE)的控制电极,其中扩散层、催化剂的性能将直接影响电解池性能的高低。采用热分解、酸浸蚀、电沉积方法,对钛氧电极扩散层基体进行表面改性研究;探讨了氧电极催化剂对WE极化性能的影响;同时考察了温度、氧电极扩散层对WE性能的影响。结果表明:电沉积法处理钛氧电极扩散层可以使电阻降低,并且在大气中搁置电阻也不会增加;IrO2-RuO2氧电极复合催化剂具有最佳的催化活性;随着电解温度升高,电解电压下降;以电沉积法处理的钛网为氧电极扩散层时,WE性能得到明显提高,在常压、70℃条件下,电解电压为1.65V时,电流密度大于1A/cm2。

Oxygen electrode is a dominant electrode of SPE water electrolyzer （WE）, of which diffusion layer and catalyst have direct influence on the performance of WE. The titanium oxygen electrode diffusion layers obtained by thermal decomposition, acid immersion, electro-deposition surface modification were evaluated. The effects of oxygen electrode catalyst, temperature, and oxygen electrode diffusion layer on the performance of WE were also discussed. The results showed that the resistance of Ti oxygen electrode diffusion layer decreased after electro-deposition treatment, and did not increase even if it was exposed to the atmosphere for a long time. IrO2-RuO2 oxygen electrode catalyst has the best catalytic characteristic. Electrolysis voltage decreased increasing temperature. The WE performance was obviously enhanced when electro-deposited Ti mesh was used as oxygen electrode diffusion layer, its current density was more than 1 A/cm^2 at atmosphere pressure,70℃, 1.65 V.