5-(4-chlorophenyl)-1H-tetrazole as an effective corrosion inhibitor for mild steel used in oil and natural gas industries

Abstract

The effect of 5-(4-chlorophenyl)-1H-tetrazole (Cl-PTZ) on corrosion inhibition of mild steel in 1M HCl was investigated by weight loss measurement, open circuit potential(OCP), potentiodynamic polarization and surface measurements. Results showed that the inhibition efficiency increased with increase in concentration of inhibitor and attained the maximum value at 500 ppm concentration. Polarization study revealed that 5-(4chlorophenyl)-1H-tetrazole acted as mixed-type inhibitor. Among the several tested isotherms, adsorption of 5-(4-chlorophenyl)-1Htetrazole on the mild steel surface obeyed the Langmuir adsorption isotherm. The adsorption of corrosion inhibitor on mild steel surface is well supported by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) study.

Study of Corrosion Inhibition of Mild Steel in 0.1n Hcl Solution Using 3-[(4-Methoxy Phenyl)Imino]-1,3-Dihydro-2H- Indole-2-One

“…There was also a decrease in the oxygen content, but it was not as significant as the chlorine content, this can be attributed to the fact that the used inhibitor contains oxygen moiety that can get adsorbed on the metal surface. This proves that the used inhibitors protect the mild steel sample from the corrosive media [22,23,25].…”

“…From Fig ( 10c), it is observed that there is no deterioration of the mild steel coupon. This proves that the used inhibitor gets adsorbed on the metal surface and forms a protective film, thus protecting it from a corrosive solution [22,23,25].…”

“…In the presence of different concentrations of the used inhibitor, the steady state potential is shifted towards the anodic side. This implies that the used inhibitor gets adsorbed on the metal surface and forms a protective layer on the mild steel surface [21][22][23].…”

“…Furthermore, if there is no shift observed in the Ecorr values then the adsorption process is carried out by blocking effect. From Table (5), there was a slight difference in the Ecorr values, which indicates that the used inhibitor inhibited the metal surface by blocking effect as well as altered the activation energies of both cathodic and anodic reactions [22][23][24].…”