Nitrogen and Phosphorus Doped Activated Carbon Catalyst Prepared from Shrimp Shell and its Application in MFC Air Cathode

Abstract

AbstractCathode design and cost is one of the major challenges for microbial fuel cell (MFC) large scale operation due to the adoption of precious Pt/C catalyst. In this work, shrimp shells were chosen to prepare a cheap and sustainable ORR catalyst and applied it in MFC air cathode. Single step pyrolysis and activation at 700 °C with H3PO4 was used to introduce phosphorus atom in the carbon. Three types of catalysts, named shrimp shells activated carbon (SS‐AC), commercial activated carbon (C‐AC) and Pt/C were compared for their performance in MFC system. The results showed that SS‐AC had high porous surface that contained nitrogenous and phosphorous functionalities at a significant percentage with high surface area of about 448.96 m2 g−2. The maximum power density achieved by the MFC that used SS‐AC catalyst was 1207±15 mW m−2 at 3.14 A m−2, 12 % less than Pt/C and 44 % higher than those of the C‐AC. The coulombic efficiency of 67 % was also achieved with this MFC slightly lower than those by Pt/C and higher than those by C‐AC. The good performance of this material was mainly due to the double doped heteroatoms which increases the oxygen reduction sites on the surface of the carbon.