Inhibition by tetradecylpyridinium bromide of the corrosion of aluminium in hydrochloric acid solution

The inhibition effect of tetradecylpyridinium bromide (TDPB) on the corrosion of aluminium in 1.0 M HCl solution was studied by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods. The results show that TDPB is a very good inhibitor at little concentrations, and the adsorption of TDPB on aluminium surface obeys Langmuir adsorption isotherm. Polarization curves reveal that TDPB behaves as a cathodic inhibitor. EIS spectra consist of large capacitive loop at high frequencies followed by a large inductive one at low frequency values, and confirm the inhibitive ability.

Research highlights
► Tetradecylpyridinium bromide (TDPB) is found to be a good inhibitor for the corrosion of alunimium in 1.0 M HCl.
► The adsorption of TDPB on aluminium surface obeys Langmuir adsorption isotherm.
► TDPB acts as a cathodic-type inhibitor.
► EIS diagram appears an elliptic shape. The presence of TDPB in 1.0 M HCl solutions enhances Rt values while reduces Cdl values.