Investigation of the effect of piperidin-1-yl-phosphonic acid on corrosion of iron in sulfuric acid

Abstract The inhibitive effect of the piperidin-1-yl-phosphonic acid (PPA) on the corrosion of iron in 1 M H 2 SO 4 solution has been investigated by weight loss measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The presence of (PPA) reduces remarkably the corrosion rate of iron in acidic solution. The effect of temperature on the corrosion behavior of iron was studied in the range of 298–328 K. Results clearly reveal that the (PPA) behaves as a mixed type corrosion inhibitor with the highest inhibition at 5 × 10 −3  M. The adsorption of PPA on the iron surface obeys the Langmuir's adsorption isotherm.