La(1-x)SrxCoO3(x=0,0.2,0.4,0.6,0.8)钙钛矿型氧化物的催化性能及改性

Electrocatalytic Properties and Modification of La_(1-x)Sr_xCoO_3(x=0, 0.2, 0.4, 0.6, 0.8) Perovskite Oxide

通过溶胶-凝胶法制备出A位Sr掺杂的钙钛矿型氧化物La_(1-x)Sr_xCoO_3(x=0,0.2,0.4,0.6,0.8),并将其作为催化剂应用于双功能氧电极中。测试结果表明,A位Sr的掺杂的La_(1-x)Sr_xCoO_3比LaCoO_3具有更高的电催化活性,并且La_(0.6)Sr_(0.4)CoO_3在氧还原和氧析出反应中均表现出最优的催化性能,最大电流密度分别达到0.244 A·cm^(-2)(-0.6 V vs Hg/HgO)和0.303 A·cm^(-2)(1 V vs Hg/HgO)。为进一步提高催化剂的催化活性,将水热法制备的α-MnO_2纳米管与La_(0.6)Sr_(0.4)CoO_3复合作为双功能催化剂。当α-MnO_2的质量分数为40%时,比起单一的α-MnO_2或钙钛矿氧化物,α-MnO_2/La_(0.6)Sr_(0.4)CoO_3复合材料表现出协同效应,有更好的双功能电催化活性,使双效氧电极具有更好的电化学性能及稳定性。

The Sr-doped perovskite oxides La1-xSrxCoO3 （x=0, 0.2, 0.4, 0.6, 0.8）, as the electrocatalyst for bi- functional oxygen electrode, were synthesized by sol-gel method. The test results show that Sr-doped La1-xSrxCoO3 has higher electrocatalytic activities than LaCoO3. In addition, Lao.6Sr0.4CoO3 reveal excellent catalytic activity for the oxygen evolution reaction and oxygen reduction reaction, reaching a maximum of 0.244 A. cm-2 （at -0.6 V vs Hg/HgO） and 0.303 A·cm-2 （at 1 V vs Hg/HgO）. In order to further improve the catalytic activity of the catalyst, α-MnO2 nano-wires as bi-functional catalyst was prepared by hydrothermal synthesis and added into the Lao.6Sr0.4CoO3. The activities of bi-functional catalysts of α-MnO2/La0.6Sr0.4CoO3 were markedly superior compared with α-MnO2 or La0.6Sr0.4CoO3 perovskite oxide when the mass fraction of 40% α-MnO2, demonstrating a synergistic effect, which was responsible for the improvement of electrochemical catalytic activity and stability of the bifunctional oxygen electrode.