La1-xSrxCoC3钙钛矿在碱性溶液中的析氧电催化

 稳态极化研究结果表明, La1-xSrxCoO3电极的析氧Tafel斜率为2303RT/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.

Electrocatalysis of Oxygen Evolution on La1-xSrxCoO3 Perovskites in Alkaline Solution

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.