The Development of Anion Exchange Ionomer for Electrocatalysts in Application of Anion Exchange Membrane Fuel Cells

Monday, 10 October 2022
T. R. Maumau, N. W. Maxakato, and P. F. Msomi (University of Johannesburg)
Anion exchange membrane fuel cells (AEMFCs) are known to be able to address the use of expensive platinum catalyst by employing non-PGMs (Platinum Group Metal) metal catalysts, affordable ionomers, and greater fuel flexibility. All that provides AEMFCs with advantages over PEMFCs. However, AEMFCs have not been reported to achieve high current density as desired at fault by the lack of understanding of ionomer-catalyst interaction. For stable operation of AEM-based devices, water sorption and swelling of the thin anion exchange ionomer (AEI) layer are coupled to its catalyst binding ability. Unfortunately for AEM fuel cell field there exists no commercial material as Nafion® exists for the PEM fuel cell field. The development of a high performance and durable anionic catalyst binders also referred to as anion exchange ionomers (AEIs) is the major challenge for AEMFCs. This study aims to develop an improved AEI to be tested in both in-house and commercial electrocatalysts. Electrocatalytic activity using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and chronoamperometry (CA) will be carried out for all the electrocatalysts with the use on the developed AEI instead of the usually used nafion ionomer. Characterization techniques will include transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) for particle size, crystal structure and morphology respectively of the electrocatalysts. For the developed AEI dynamic light scattering (DLS) (with an ELS-Z Zeta-potential and particle size analyzer), nuclear magnetic resonance (NMR), and Fourier-transform infrared spectroscopy (FTIR) for size distribution profile, material molecular structure and composition.