La_(1-x)Sr_xNi_(1-y)Co_yO_3双功能氧电极的电化学性能  

Electrochemical Properties of La_(1-x)Sr_xNi_(1-y)Co_yO_3 Bifunctional Oxygen Electrodes

作　　者：唐致远[1] 宋世栋[1] 刘建华[1] 潘丽珠[1] 南俊民[2] 

机构地区：[1]天津大学化工学院应用化学系,天津300072 [2]华南师范大学化学系,广州510631

出　　处：《物理化学学报》2003年第9期785-790,共6页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(20020056045)~~

摘　　要：采用溶胶-凝胶法制备了一系列La_(1-x)Sr_xNi_(1-y)Co_yO_3(x=0、0.1、0.2、0.5;y=0～1.0)型的钙钛矿催化剂,并以活性碳为载体制备双功能氧电极.对催化剂进行了XRD结构分析以及XPS表面分析.采用三电极体系测试了氧电极的稳态极化曲线和电化学交流阻抗谱并对其阴极极化和阳极极化谱图进行了分析.实验表明,对于LaNiO_3化合物,B位掺杂可显著提高催化剂表面的B离子浓度,从而提高电催化性能;而A位掺杂由于导致有序化氧空位的增多和电导的降低而造成活性下降.电极氧还原反应的极化主要由电荷转移反应和能斯特扩散过程造成.A series of novel La1-x SrxN1-yCoyO3( x = 0, 0. 1, 0. 2, 0. 5; y = 0 - 1. 0)perovskite oxides were prepared by sol-gel method and characterized by XRD and XPS. The activity of bifunctional oxygen electrodes made by the perovskite-type catalyst dispersed on active carbon were investigated using electrochemical impedance spectroscopy(EIS). The impedance spectra of both cathodic and anodic polarization were analyzed. The results show that the properties of electrodes are improved by doping Co3+ ions on B site because the concentration of B site ions on the catalysts surface are increased. But by doping Sr2 + ions on A site could impair the effect because the ordering level of oxygen vacancy and the electrode resistance are increased. The polarization resistance is mainly caused by the slow Nernstian diffusion and charge transfer reaction and not by concentration of adsorption of oxygen species and oxygen vacancy. So it is concluded that by increasing the concentration of B site ions on perovskite oxide surface and improving the thickness of electrolyte film the performance of oxygen electrodes could by improved.

关 键 词：Lal-xSrxNi1-yCoyO3双功能氧电极 电化学性能 金属-空气电池 钙钛矿复合氧化物 电化学阻抗谱 燃料电池 电极材料 

分 类 号：O646.54[理学—物理化学]