Carbon-Supported Cu-Doped Mn-Co Spinel-Type Oxides Used as Cathodic Catalysts for the Oxygen Reduction Reaction in Dual-Chambered Microbial Fuel Cells

In this study, carbon-black-supported Cu-doped Mn-Co spinel-type oxides (MnxCu1-xCo2O4/C, x= 0, 0.2, 0.4, 0.6, 1) were synthesized by using a hydrothermal method. Firstly, the morphology characterization shows that the as-prepared MnxCu1-xCo2O4 nanoparticles with the crystalline spinel structure are uniformly dispersed on the carbon black and the MnxCu1-xCo2O4/C samples possess high specific surface area. The neutral oxygen reduction reaction (ORR) performance of MnxCu1-xCo2O4/C evaluated by cyclic voltammetry (CV) shows that all catalysts can catalyze the ORR. Mn0.6Cu0.4Co2O4 /C exhibited the highest catalytic activity, which might be due to its highest surface area. Finally, the MnxCu1-xCo2O4/C samples were used for microbial fuel cells (MFCs) as cathodic catalysts. The polarization curves demonstrate that Mn0.6Cu0.4Co2O4/C owns the best power output, close to 20 wt% Pt/C. This study suggests that using Mn0.6Cu0.4Co2O4/C instead of Pt/C could potentially improve the feasibility of scaling up MFCs for real applications by lowering the production cost.