Poly( m ‐phenylenediamine)‐coated 316L SS: A promising material for bipolar plates in PEMFC environment

The applicability of conducting polymer coatings to enhance corrosion resistance of bipolar plates in proton exchange membrane fuel cells (PEMFC) is gaining greater significance as electrical conductivity is as important as corrosion resistance. Metaphenylenediamine ( m PD) monomer was electropolymerized to poly( m ‐phenylenediamine) (P m PD) conducting polymer over 316L SS and characterized by attenuated total reflectance infrared spectroscopy to confirm the formation of P m PD polymer. Scanning electron microscopy was used to study the surface morphology of the polymer. Open‐circuit potential, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization studies were conducted to assess the corrosion protection performance of the P m PD polymer coating in PEMFC environment. The charge‐transfer resistance measured from EIS for the coated substrates was higher than the uncoated substrate. Potentiodynamic polarization studies showed lower corrosion current density for the P m PD‐coated substrates. All the results proved that the P m PD‐coated substrates could exhibit enhanced corrosion resistance in PEMFC environment.