2-Mercaptobenzothiazole as a corrosion inhibitor for carbon steel in supercritical CO2-H2O condition

Abstract The corrosion inhibition performance of 2-mercaptobenzothiazole (MBTH) for carbon steel in a CO 2 -H 2 O system was investigated by weight loss, surface analysis, electrochemical measurements, and quantum chemical calculations. Results showed that MBTH could effectively protect carbon steel from CO 2 corrosion and inhibition efficiency of MBTH in supercritical CO 2 was higher than that in non-supercritical CO 2 situation. The differential capacitance curves revealed that excess positive charges would be on the surface of carbon steel in the supercritical-CO 2 system while negative charges accumulated on carbon steel surface in non-supercritical CO 2 condition. The adsorption model was proposed to explain the inhibition mechanism of MBTH.