This study focused on the use of spinel manganese–cobalt (Mn–Co) oxide, prepared by a solid state reaction,
as a cathode catalyst to replace platinum in microbial fuel cells (MFCs) applications. Spinel Mn–Co
oxides, with an Mn/Co atomic ratios of 0.5, 1, and 2, were prepared and examined in an air cathode MFCs
which was fed with a molasses-laden synthetic wastewater and operated in batch mode. Among the
three Mn–Co oxide cathodes and after 300 h of operation, the Mn–Co oxide catalyst with Mn/Co atomic
ratio of 2 (MnCo-2) exhibited the highest power generation 113 mW/m2 at cell potential of 279 mV,
which were lower than those for the Pt catalyst (148 mW/m2 and 325 mV, respectively). This study indicated
that using spinel Mn–Co oxide to replace platinum as a cathodic catalyst enhances power generation,
increases contaminant removal, and substantially reduces the cost of MFCs.