Ag修饰La_(0.8)Sr_(0.2)CoO_3空气电极电催化性能

Electrocatalytic performance of Ag/La_(0.8)Sr_(0.2)CoO_3 air electrode for oxygen reduction

采用溶胶-凝胶法合成了钙钛矿型La0.8Sr0.2CoO3复合氧化物,并选用Ag对其进行修饰,获得Ag/La0.8Sr0.2CoO3纳米粉体,利用XRD、XPS方法对催化剂的结构与组成进行表征;然后将该粉体作为催化材料制备出空气电极,在碱性介质中,通过测量空气电极的稳态极化曲线和交流阻抗谱,考察Ag含量对催化剂的电催化活性的影响.研究发现,Ag的加入增强了La0.8Sr0.2CoO3复合氧化物的导电性,并对电极材料的催化活性起到一定的促进作用;当Ag的质量分数为8%时,Ag/La0.8Sr0.2CoO3氧化物电极材料催化活性较高.

The catalyst La0.8Sr0.2CoO3 with the perovskite -type structure was prepared using citric acid sol - gel method, and then modified with Ag. The structure and constitution of Ag/La0.8Sr0.2CoO3 were characterized by the XRD and XPS techniques. Furthermore, air electrodes were prepared using the obtained powder as catalyst layer materials. In alkaline solution, the effect of doped Ag content on the electrocatalytic activity of the prepared materials was studied by investigating corresponding polarization curve and electrochemical impedance spectroscopy （EIS）. The results showed that the electrical conductivity of the complex oxides La0.8Sr0.2CoO3 and the electrocatalytic activities of La0.8Sr0.2CoO3 electrode materials could be evidently enhanced by the addition of Ag. When the Ag content in the Ag/La0.8Sr0.2CoO3electrode materials is 8%, the electrocatalytic activity is the highest.