Microbial fuel cells (MFC) are bioelectrochemical systems that convert the chemical energy contained in waste to electricity, using bacteria as catalysts. In order to boost the power output of MFCs, various approaches are feasible. This study examines the effect of using MnO2, activated carbon and fly ash as catalysts on the performance of three identical single-chamber MFCs. Ceramic (mullite) tubes run through the chamber providing structural support to the catalyst. Graphite granules were used as the anode electrode for all units. The cells operated in batch mode using glucose (1.5 g COD/L) as substrate. High COD removal efficiencies (>75%) were achieved for all units. The best performance in terms of power output was achieved when using MnO2 catalyst (Pmax=2.32 W/m3).