LaMnCoNi_(x)O_(3)中Ni掺杂对氧还原/氧析出反应活性的影响

The effects of Ni dopant in LaMnCoNi_(x)O_(3) catalysts on the oxygen reduction/evolution activity

采用溶剂热法制备LaMnCoNi_(x)O_(3)(x=0.1、0.2和0.3)球体钙钛矿氧化物催化剂,该球体催化剂由厚度约为50 nm的纳米片构成,直径大约为1μm。通过高倍扫描电镜、高倍透射电镜、X射线衍射和X射线光电子能谱对催化剂进行物理表征,并采用三电极体系对催化剂进行电化学表征。研究结果表明Ni的掺入可以显著提升LaMnCoNi_(x)O_(3)催化剂的氧还原(ORR)活性和氧析出(OER)活性。当Ni的掺入为0.2时,其ORR和OER活性均最优:ORR半波电位为0.716 V(Hg/HgO,RHE);在电流密度为10 mA/cm^(2)时,OER过电位为410 mV(@1.23 V vs.RHE)。上述结果表明,合理的Ni掺入可以有效地提高催化剂的ORR/OER活性。

A series of LaMnCoNi_(x)O_(3)(x=0.10.2 and 0.3)perovskite-type oxide catalysts were prepared by polyolassisted solvothermal method.These spheroidal catalysts consisted of about 50 nm nanoplatelets with a approximately diameter of 1μm.The physical properties of the catalyst were characterized by high-resolution scanning electron microscope,high-resolution transmission electron microscope,X-ray diffraction,and X-ray photoelectron spectroscopy.The electrochemical properties were tested in a three-electrode device.The results showed that the incorporation of Ni significantly improved the ORR and OER activity of the LaMnCoNi_(x)O_(3) catalyst.When the Ni content was 0.2,its ORR and OER activities were the best.In LaMnCoNi0.2O3 catalyst,the half-wave potential is 0.716 V(Hg/HgO,RHE),and its over-potential at 10 mA/cm2 was 410 mV(@1.23 V vs.RHE).The results show that the reasonable incorporation of Ni improves the ORR/OER activity of LaMnCoNi_(x)O_(3) catalyst effectively.