In this work, the role of cation occupancy in spinels through partial inversion for hightemperature oxygen-evolving reactions is explored. We synthesized a combination of double spinels, and their catalytic activities are examined for the oxygen-evolving reaction. The distribution of cations in more than one oxidation state enhances the catalytic activity of FeCo2O4/SiC-Pretrt. The high catalytic activity and stability could be attributed to the presence of octahedral and tetrahedral active sites in FeCo2O4 /SiC-Pretrt. It is expected that the approach discussed in this work will provide a tool for precisely tailoring chemical properties by accommodating cations in more than one oxidation state for enhanced catalytic activity. To the best of our knowledge, this FeCo2O4 /SiC-Pretrt shows, so far, the best performance among all reported spinel-based metal oxides in this reaction. This work would lead to revisiting other spinel nanocatalysts in different heterogeneous reactions where functionality is vital in improving reaction performance.