Effect of methanol on the corrosion behaviour of Al-Cu Alloys in sulphuric acid

Abstract

The effect of Cu additions (1, 3 and 5 at.-%) on the corrosion behaviour of Al in 0.5 M H₂SO₄ + 2 ppm hydrofluoric acid + methanol at 50°C, environment found in a direct methanol fuel cell, has been evaluated using electrochemical techniques. Electrochemical techniques included potentiodynamic polarisation curves, electrochemical impedance spectroscopy and electrochemical noise measurements measurements. Methanol concentrations included 1, 5, 10 and 20 M. Results have shown that corrosion resistance increases with increasing the methanol concentration. The addition of Cu to Al increases the corrosion rate of the former by the formation of micro galvanic cells, inducing localised typo of corrosion also.