Inhibition of Aluminium Corrosion in 1M HCl by Pyridoxine Hydrochloride: Thermodynamic and Quantum Chemical Studies

Currently, research in the area of corrosion inhibition is focussed on the development of green corrosion inhibitors. It is with this in mind that pyridoxine hydrochloride, which is vitamin B6, has been tested as a corrosion inhibitor of aluminium in 1M HCl by mass loss, Density Functional Theory (DFT) and Quantitative Structure-Property Relationship (QSPR) methods. The results obtained show that the inhibition efficiency increases with concentration but decreases with increasing temperature. This vitamin is adsorbed on aluminium according to the modified Langmuir isotherm and occurs in two modes: physisorption and chemisorption. Thermodynamic adsorption and activation parameters have been determined and discussed. Finally, QSPR approach was used to find the best set of parameters in order to determine the theoretical inhibition efficiencies from the experimental data. Experimental measurements were found in good collaboration with the theoretical results.