Mass‐Production of Mesoporous MnCo₂O₄ Spinels with Manganese(IV)‐ and Cobalt(II)‐Rich Surfaces for Superior Bifunctional Oxygen Electrocatalysis

A mesoporous MnCo 2 O 4 electrode material is made for bifunctional oxygen electrocatalysis. The MnCo 2 O 4 exhibits both Co 3 O 4 ‐like activity for oxygen evolution reaction (OER) and Mn 2 O 3 ‐like performance for oxygen reduction reaction (ORR). The potential difference between the ORR and OER of MnCo 2 O 4 is as low as 0.83 V. By XANES and XPS investigation, the notable activity results from the preferred Mn IV ‐ and Co II ‐rich surface. The electrode material can be obtained on large‐scale with the precise chemical control of the components at relatively low temperature. The surface state engineering may open a new avenue to optimize the electrocatalysis performance of electrode materials. The prominent bifunctional activity shows that MnCo 2 O 4 could be used in metal–air batteries and/or other energy devices.