High Performance Pd-CeO _2-NR Supported on Graphene and N-Doped Graphene for the ORR and Its Application in a Microbial Fuel Cell

Abstract

In this work, novel electrocatalysts based on Pd and cerium oxide nanorods (CeO2-NR) were synthesized by the NaBH4 method. Moreover, home-obtained graphene (G) and N-doped graphene (GD1) were used as supports. The cathodes were identified as Pd-CeO2-NR/G, Pd-CeO2-NR/GD1. The electrocatalysts showed higher catalytic activity for the Oxygen Reduction Reaction (ORR) than Pd/C and comparable to Pd-CeO2-NR/C (supported on Vulcan) in 0.5 mol L-1. In the dual-chamber MFC, the anode substrate was actual pharmaceutical residual water (PRW) from a local company, while KOH (pH = 9.6) was the electrolyte in the cathode compartment. Pd-CeO2-NR/GD1 showed a higher performance as cathode in the cell compared to Pd/C and commercial Pt/C, delivering an open circuit voltage of 0.26 V and a maximum power density of 12.47 mW m-2. Thus, this novel electrocatalyst based on CeO2-NR and GD1 is a promising alternative to increase the performance of MFCs.