Ru-Co-Ce复合氧化物阳极制备及析氧性能研究

Preparation of Ru-Co-Ce Electrode and Its Oxygen Evolution Performance

摘要:

采用溶胶-凝胶法制备RuO2-Co3O4-CeO2(Ru-Co-Ce)复合氧化物电极，对制备电极的热处理温度和稀土CeO2含量进行了优化。利用SEM、XRD分析方法对电极表面形貌进行表征，通过开路电压(Eoc)、循环伏安(CV)及阳极极化曲线等手段研究电极在1.0 mol·L-1 KOH溶液中的析氧催化活性。结果表明，制备温度对电极表面形貌有很大影响(优选400 ℃)，复合氧化物电极中适量稀土CeO2可增强电极表面致密性，使RuO2晶相衍射峰减弱，峰形宽化，提高电极活性表面积，促进活性组分RuⅢ/ RuⅣ间的转化，使析氧过电位降低60 mV，从而提高电极析氧反应的活性，Ce最佳比例为0.4(摩尔分数)

Abstract:

RuO2-Co3O4-CeO2(Ru-Co-Ce) composite oxide electrodes were prepared by sol-gel process. The parameters of electrode preparation, including the heat treatment temperature and CeO2 doping content, were optimized. The morphology and composition of the anode surface were characterized by SEM and XRD, respectively. Electrocatalytic activity of these electrodes in 1.0 mol·L-1 KOH solution were studied by means of open-circuit potential (Eoc), cyclic voltammetry (CV), voltammetric charge (q*) and polarization curve. The results show that the preparation temperature influenced electrode surface morphology greatly, and the optimal temperature was 400 oC. The CeO2 of appropriate content could increase the active surface area, reduce the grain size and enhance the electrical conductivity of the electrodes, which was in favor of catalytic reactions and redox transition from RuⅢ to RuⅣ. The anodic overpotential for oxygen evolution was decreased by 60 mV and thus the activity of oxygen evolution was improved. The maximum activity was observed with the Ce content of 0.4 mol%