空气电极催化剂LA_(2-X)SR_X CUO_(4+Λ)在氧还原反应中的催化活性研究

Electrocatalytic performances of perovskite - like complex oxides La(2-x)Sr_xCuO(4+λ) air electrode catalyst for oxygen reduction

合成了LA2-XSRXCUO4+Λ(0≤X≤1)系列类钙钛矿复合氧化物,并作为催化层电极材料制备了空气电极,在碱性介质中以HG/HGO为参比电极测量了电极的极化曲线、循环伏安和交流阻抗,考察了组成对催化剂的电催化活性的影响。研究发现LA2-XSRXCUO4+Λ型类钙钛矿复合氧化物电极材料催化活性较高,并且活性随SR掺杂量的不同活性也有所变化。EIS测试结果表明:不同配比的LA2-XSRXCUO4+Λ型类钙钛矿复合氧化物电极阻抗谱均由一个半圆和一个拖尾直线组成,并提出了空气电极的等效模拟电路,得到了模拟值,对拟合的动力学参数进行了解释。

A series of perovskite - like complex oxides La2-xSrxCuO4＋λ （0 ≤x ≤ 1 ） were prepared. The air electrode with different mass ratio of Sr as catalyst layer was prepared in alkaline solution. The electrocatalytic performances for oxygen reduction were evaluated by means of polarization curve, cyclic voltammetry and electrochemical impedance spectroscopy（EIS） by using Hg/HgO as a reference electrode. The results showed that La2-xSrxCuO4＋λ （0≤ x ≤ 1 ） had excellent activity and the activity changed with the different ratio of Sr. The EIS consisted of a half circle and a trailing straight line. The low frequency zone was ascribed to the diffused process and the high frequency zone to the electrochemical kinetic process. The equivalent circuit of the air electrode was proposed and the simulated kinetics data were analyzed.