A study of 4-carboxyphenylboronic acid as a corrosion inhibitor for steel in carbon dioxide containing environments

• 4-Carboxyphenylboronic acid has promise in new inhibitor systems in corrosion engineering.
• The improved inhibition performance with increasing of the inhibitor concentration.
• 4-Carboxyphenylboronic acid promotes the formation of a barrier protective film.
• The inhibitor mitigates localized corrosion by promoting random distribution of minor anodes.

4-Carboxyphenylboronic acid (CPBA) has been found to be an efficient carbon dioxide (CO2) corrosion inhibitor for steel in aqueous media. The results indicate that the addition of CPBA to CO2 containing sodium chloride solutions at a low concentration is able to retard corrosion anodic reactions, reduce corrosion current densities, increase charge transfer and total resistances, resulting in more uniform and smoother steel surfaces. These effects are attributed to the formation of a barrier layer on steel surface, which provides metal surface protection. The inhibitor was also found to mitigate corrosion by promoting random distribution of minor anodes.