氧还原催化剂LaMn_(1-y)Cr_yO_3的制备与性能

Preparation and performance of LaMn_(1-y)Cr_yO_3 catalysts for oxygen reduction

采用溶胶-凝胶法制备锌-空气电池用氧还原催化剂LaMn1-yCryO3(y=0,0.1,0.2,0.3,0.4,0.5)。XRD分析表明:合成的LaMn1-yCryO3样品具有钙钛矿型结构。TEM测试表明:样品的平均粒径有所不同,其中LaMn0.8Cr0.2O3的平均粒径较小(20 nm),分散程度好。以LaMn1-yCryO3为催化剂制备空气电极,极化特征测试结果表明:所制备的催化剂具有良好的氧还原电催化性能,且LaMn0.8Cr0.2O3电催化性能最佳,在电极电位为-200 mV(vs.Hg/HgO)时,输出电流密度为70 mA/cm2。

LaMn1_ yCryO3（y = 0,0.1,0.2,0.3,0.4,0.5） catalysts for the oxygen reduction of zinc-air cells were prepared by sol-gel method. XRD analysis showed that the prepared LaMnl_ yCryO3 samples had perovskite structure. Transmission electron microscopy （TEM） analysis showed that the mean particle size of the prepared samples had difference. LaMn0.8Cr0.2O3 sample had a smaller mean particle size（20 nm） and higher dispersion. The polarization characteristic test of air electrodes with the LaMn1- yCryO3 catalysts was investigated. The test results showed that the prepared catalysts had good electrocatalytic activity for the oxygen reduction and the best electrocatalytic activity was achieved when the composition was fixed at LaMn0.8Cr0.2O3 with output current density of 70 mA/cm^2 at the electrode potential of - 200 mV （ vs. Hg/HgO）.