The effect of some organophosphorus compounds on the corrosion behaviour of iron in 6 M HCI

The effect of some organophosphorus compounds on iron corrosion in 6 M HCl has been examined by means of polarization and capacitance measurements. It appears that these compounds inhibit iron corrosion by affecting both cathodic and anodic reactions. A quantum chemical approach was used to correlate the inhibition efficiency to the molecular structure of the compounds. It was found that there is not a noticeable relationship between their molecular structure and their inhibition effectiveness. Also based on these calculations, it can be suggested that the inhibitor molecules behave as electron acceptor when they adsorb on the iron metal.