In recent years, spinels have proven to be a rich source of earth abundant metal oxide catalysts capable of catalyzing OER efficiently . Most spinel oxides reported for OER tend to be Fe-based or Co-based, with some examples of highly active spinel oxides being NiFe2O4, CoFe2O4 and CuCo2O4 . For example, Liu and coworkers fabricated NiFe2O4 nanospindles on an Fe3Ni foam substrate that exhibited an overpotential of 262 mV at a current density of 10mA.cm -2 , as well as a Tafel slope of 39.5mV.dec -1 in 1M KOH . Lu and coworkers synthesized CoFe2O4 nanoparticles on carbon nanorods that had an overpotential of 240mV at 10mA.cm -2 as well as a Tafel slope of 45 mV.dec -1 in 1M KOH . Yadav and coworkers synthesized 3D CuCo2O4 nanoflowers on a carbon cloth substrate that had an overpotential of 288mV at 10mA.cm -2 and a Tafel slope of 64.2 mV.dec -1 in 1M KOH . The efficacy of these catalysts demonstrate that spinels could be a promising source of new materials for OER catalysis. However, while considerable work has been done so far to discover new spinel oxide catalysts for OER, the entire possible chemical space of spinels has yet to be explored. There could potentially be more efficient spinel oxide catalyst compositions that haven't been discovered yet.