Enhanced Oxygen Reduction Performance on {101} CoMn2O4 Spinel Facets

Here, we present a facile colloidal synthesis method for producing {101}-facet-tailored CoMn₂O₄ spinel nano-octahedra with uniform size (9 nm). These nano-octahedra exhibit superior electrocatalytic activity for the oxygen reduction reaction (ORR) in alkaline media compared to their spherical counterparts and previously reported spinel electrocatalysts. At 0.85 V, they achieve a high mass activity (MA) of 60.0 A/g, surpassing the spherical counterparts (38.6 A/g). Furthermore, the CoMn₂O₄ nano-octahedra demonstrate excellent stability, maintaining an MA of 47.2 A/g after 10,000 durability cycles. This work highlights a promising approach for synthesizing advanced spinel nano-oxides with controlled crystal facets, offering potential as non-precious metal ORR electrocatalysts. The exposed active catalyst surfaces and well-defined structures contribute to their enhanced ORR performance.