Corrosion behaviour of austenitic stainless steel as a function of methanol concentration for direct methanol fuel cell bipolar plate

摘要: Abstract The corrosion behaviour of an AISI 304 stainless steel (304 SS) is investigated in aqueous acid methanol solutions (0.5 M H 2 SO 4  + 2 ppm HF +  x  M CH 3 OH,  = 0, 1, 5, 10 and 20) at 50 °C to simulate the varied anodic operating conditions direct fuel cells. Electrochemical measurements including potentiodynamic polarisation, potentiostatic polarisation electrochemical impedance spectroscopy tests, are employed analyse behaviour. results reveal that resistance SS enhanced with higher content. Scanning electron microscopy inductively coupled plasma atomic emission spectrometry data indicate surface on alleviated when concentration increased. According X-ray photoelectron Mott–Schottky analyses, passive films formed after tests all test composed a duplex electronic structure external n-type semiconductor layer internal p-type layer. Further analyses conductivity conducted by measuring interfacial contact between carbon paper film solution content exhibits lower conductivity.