Polyacrylic co-maleic acid as an anti-scaling binder for air–cathode microbial fuel cell: An oxygen reduction reaction perspective

Abstract

Polydimethylsiloxane (PDMS) is a binder commonly used in air–cathode MFC fabrication. Herein, the performance of poly acrylic co-maleic acid (PMA) as a binder and anti-scaling agent for cathode was evaluated for application in an air–cathode MFC. Two different cathode catalysts were tested for applicability in MFC, viz., (a) Vulcan-XC: with PMA (MFC-1), with PDMS (MFC-3), and (b) Nitrogen-doped carbon catalyst (NDCP) with PDMS (MFC-2) and with PMA (MFC-4). The PMA, as an alternative to costly PDMS, prevented scale formation on the cathode surface and helped to sustain the performance of MFC-3 and MFC-4 for over 30 days. As evidenced by the cyclic voltammetry and electrochemical impedance spectroscopy, MFC-4 (NDCP and PMA) showed the best cathodic current density owing to the core–shell structure formed by nitrogen and carbon atoms in NDCP. In the future, using PMA can prevent scale formation over the (air) cathode surface and deliver a stable performance of MFC without any need for costly binder agents, such as PDMS.

Keywords

• Oxygen reduction reaction
• Nitrogen-doped carbon catalyst
• Anti-scaling
• Electrochemical impedance spectroscopy
• Microbial fuel cell