La_xSr_(1-x)NiO_3复合氧化物化学电极动力学研究  

Study on the chemical electrode dynamics of complex oxide La_xSr_(1-x)NiO_3

作　　者：林生岭[1] 王俊德[1] 谢春生[2] 严豸明[2] 

机构地区：[1]南京理工大学化工学院,江苏南京210014 [2]华东船舶工业学院材料与环境工程系,江苏镇江212003

出　　处：《电源技术》2003年第3期318-321,共4页Chinese Journal of Power Sources

基　　金：中国船舶总公司军工基金项目(JGZ99Z10)

摘　　要：甘氨酸燃烧法合成了LaxSr1-xNiO3复合氧化物,此陶瓷粉末具有高的比表面积,用来制备氧电极具有双功能氧电极特性。讨论了氧还原和氧析出时的电化学反应机理。在1mol·L-1KOH溶液里减少铂电极的面积,加入碘化钾催化剂可以成为4电子反应。通过不同温度下LaxSr1-xNiO3(x=0.15,0.70,0.75,1.00)的功能氧电极循环伏安曲线,得出化学动力学参数lnIc与1/T,-lnVa与1/T成直线关系,得到氧还原和氧析出的活化能;通过改变扫描速度,分析循环伏安曲线,可知氧气吸附在功能氧电极表面,同时可以看到,当加入8.6×10-3g/mL碘化钾(KI)时,两个氧化峰变成一个峰,氧析出电势从0.94V减少到0.62V(相对于饱和甘汞电极),同时氧还原峰突然下降,可以预测,通过减少铂电极面积,加热溶液,加入碘化钾催化剂,使氧电极更有效。LaxSr1-xNiO3, the ceramic powder of complex oxide with high specific surface area, was prepared by the glycine-nitrate process, a new combustion synthesizing method. It was used to prepare oxygen electrode and its cyclic voltammetry curves were mensurated. The results show that the electrode has the characteristics of bi-functional oxygen electrode and its catalytic activity is higher than that of the electrode consisting of nickel grid and ethyne black. Generally, the oxygen reduction and evolution is a two-electron chemical reaction. However, it will become a four-electron chemical reaction by adding KI catalyst and decresasing the area of Pt electrode in the 1 mol/L solution. According to the cyclic voltammetry(CV) curve of LaxSr1-xNiO3( x=0.15, 0.70, 0.75,1.00)function al oxygen electrode at various temperature, the chemical dynamic parameter ln Ic and 1/T, or -ln Va and 1/T, are both linear, while the activation energy of oxygen reduction and evolution are obtained. Oxygen is proved to be absorbed on the surface of functional oxygen electrode by changing the scanning rate and analyzing the CV curves. When 8.6×10-3 g/mL KI was added, two oxidation peaks change into one and the potential of oxygen evolution is decreased from 0.94 V to 0.62 V(vs. saturated calomel electrode), whereas the oxygen reduction peak is also descended sharply. The oxygen electrode will be more efficient by decreasing the area of Pt electrode, heating the solution and adding KI catalyst.

关 键 词：铂电极 LaxSrl-xNiO3 复合氧化物 电化学性能 氧电极 化学动力学 

分 类 号：TM910.3[电气工程—电力电子与电力传动]