Experimental and computational approach on the development of a new Green corrosion inhibitor formulation for N80 steel in 20% formic acid.

Organic acids are employed as scale dissolvers in the oil & gas industry during production to stimulate oil recovery by pumping in the formations. Corrosion of metallic surfaces in organic acid solutions poses a significant issue in the oil and gas sector. In recent years, considering the stringent environmental regulations, there has been a growing research interest in environmentally safe inhibitors. This paper explores the synthesis of 2-(3-(carboxymethyl)-1H-imidazol-3-ium-1-yl) acetate (IZ) and its first-time application for corrosion mitigation of N80 steel in 20% formic acid. A detailed experimental study involving gravimetric, electrochemical, and surface analytical techniques is reported herein. The electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) analyses suggest a rise of impedance with IZ and a mixed-type inhibition behavior, respectively. The inhibition efficiency (IE) is 99.54% at 200 mg/L at 308 K, reaching 99.4% at 363 K with the introduction of KI as a synergistic agent. Computational studies revealed that the inhibitor IZ gets protonated in the experimental environment. The protonated form shows a tendency to receive electrons from the metal surface and shows a greater energy of adsorption compared to that of the neutral form.

Polyethyleneimine Functionalized Graphene Oxide: A Promising Inhibitor for Corrosion of Copper in the Hydrochloric Acid Environment.

Polyethyleneimine functionalized graphene oxide (PEI-GO) was prepared and characterized for its molecular structure and morphology. The PEI-GO is, for the first time, reported as an inhibitor against copper (Cu) corrosion in 0.5 M HCl using electrochemical studies. PEI-GO acts as a promising corrosion inhibitor for Cu with 92.24% efficiency at 100 mgL-1. The PDP studies reveal a mixed type of inhibitor behavior of PEI-GO with cathodic prevalence. Cyclic voltammetry revealed the inhibition influence of PEI-GO on the redox process of Cu corrosion. SEM and FTIR-ATR studies showed the creation of a protective layer on the Cu substrate. DFT studies revealed that the PEIGO exhibits better reactivity compared to parent PEI, and Monte Carlo simulations showed higher adsorption energy for PEI-GO on the Cu surface compared to the PEI.