APPARATUS COMPRISING MANGANESE-COBALT SPINEL OXIDE/CARBON CATALYST

Provided is an apparatus containing, as a cathode catalyst, a metal oxide/carbon catalyst composition. The metal oxide/carbon catalyst composition includes 40 to 95 wt % porous Mn—Co spinel oxide nanoparticles of the formula MnCoO. The nanoparticles have an octahedral morphology, an average particle size of 5-100 nm, and average pore sizes of 1-5 nm (where x is the atomic fraction of manganese and 3-x is the atomic fraction of cobalt). The metal oxide nanoparticles are supported on a carbon substrate that contains at least 96 atomic % carbon.