La_(1-x)Sr_xCoO_3钙钛矿在碱性溶液中的析氧电催化  

Electrocatalysis of Oxygen Evolution on La_( 1- x)Sr_xCoO_3 Perovskites in Alkaline Solution

作　　者：王鹏[1] 姚立广[1] 王明贤 吴维[1] 

机构地区：[1]中国科学院金属研究所腐蚀与防护国家重点实验室,沈阳110015

出　　处：《催化学报》2000年第1期23-26,共4页

摘　　要：通过酒石酸辅助法在较低温度下合成了Ｌａ１－ ｘＳｒｘＣｏＯ３ 系列钙钛矿，研究了它们在ＫＯＨ 溶液中的阳极析氧动力学． 稳态极化研究结果表明，Ｌａ１－ ｘＳｒｘＣｏＯ３ 电极的析氧Ｔａｆｅｌ 斜率为２－３０３ ＲＴ／Ｆ， ＯＨ－ 的反应级数近似为１ ， 在阳极析氧反应中，ＯＨ－ 的电化学脱附为速度控制步骤． 随着Ｌａ１－ ｘＳｒｘＣｏＯ３ 中Ｓｒ 含量的增加，氧化物表面的粗糙度提高，当ｘ ＝０－２ 时，析氧反应的活化能最低，即Ｌａ０．８Ｓｒ０ ．２ＣｏＯ３ 表现有最高的析氧电催化活性．La 1- x Sr x CoO 3 series perovskites were synthesized by tartaric acid aided method at moderate temperature. XRD patterns were taken for each sample to confirm the compound concerned. The surface area of electrodes was determined by double layer charging curves, using the cyclic voltammetry technique. A kinetic study of the oxygen evolution on these electrodes in KOH solution was made by Tafel polarization technique. The steady state polarization results indicated that the Tafel slope of oxygen evolution on La 1- x Sr x CoO 3 electrodes is 2 303 RT/F and the reaction order with respect to OH - is close to unity. The electrochemical desorption of OH - is the rate determining step for the oxygen evolution reaction. The roughness factor of oxides increases with the increase of x in La 1- x Sr x CoO 3. The activation energy of oxygen evolution reaction on La 1- x Sr x CoO 3 with x =0 2 is the lowest, i.e. the electrocatalytic activity of La 0.8 Sr 0.2 CoO 3 is the highest among all the perovskites.

关 键 词：钙钛矿 析氧电催化 碱性溶液 阳极析氧动力学 

分 类 号：O646.31[理学—物理化学]