In-depth insight into the inhibition mechanism of pyrimidine derivatives on the corrosion of carbon steel in CO2-containing environment based on experiments and theoretical calculations

Abstract

In this work, with 2-mercaptopyrimidine (MP) as the precursor, a pyrimidine derivative, 2-benzylthiopyrimidine (BTP), is developed as inhibitor to inhibit the corrosion of carbon steel in CO2-containing environment. Electrochemical measurements indicate that MP and BTP present high inhibition performance, especially for BTP with an inhibition efficiency of 99.82 %. Theoretical calculations show that the protonation of MP and BTP hardly occurs. The benzyl substituent in BTP enhances its adsorption ability by preventing tautomeric transformation and forming hydrophobic structure. Both MP and BTP molecules can adsorb on Fe surface in a nearly vertical orientation through the bonding of N and S atoms.