Controlled synthesis of porous spinel cobalt manganese oxides as efficient oxygen reduction reaction electrocatalysts

In this article, we report a facile precursor pyrolysis method to prepare porous spinel-type cobalt manganese oxides (CoxMn3-xO4) with controllable morphologies and crystalline structures. The capping agent in the reaction was found to be crucial on the formation of the porous spinel cobalt manganese oxides from cubic Co2MnO4 nanorods to tetragonal CoMn2O4 microspheres and tetragonal CoMn2O4 cubes, respectively. All of the prepared spinel materials exhibit brilliant oxygen reduction reaction (ORR) electrocatalysis along with high stability. In particular, the cubic Co2MnO4 nanorods show the best performance with an onset potential of 0.9 V and a half-wave potential of 0.72 V which are very close to the commercial Pt/C. Meanwhile, the cubic Co2MnO4 nanorods present superior stability with negligible degradation of their electrocatalytic activity after a continuous operation time of 10,000 seconds, which is much better than the commercial Pt/C electrocatalyst.

在本文中，我们报道了一种简便的前驱体热解方法来制备具有可控形貌和晶体结构的多孔尖晶石型钴锰氧化物（CoxMn3 - xO4）。研究发现，反应中的封端剂对多孔尖晶石钴锰氧化物从立方相Co2MnO4纳米棒到四方相CoMn2O4微球以及四方相CoMn2O4立方体的形成至关重要。所有制备的尖晶石材料都表现出优异的氧还原反应（ORR）电催化性能以及高稳定性。特别是，立方相Co2MnO4纳米棒表现出最佳性能，其起始电位为0.9 V，半波电位为0.72 V，与商业Pt/C非常接近。同时，立方相Co2MnO4纳米棒具有优异的稳定性，在连续运行10000秒后其电催化活性的降低可忽略不计，这比商业Pt/C电催化剂要好得多。