Cysteine and cerium as green corrosion inhibitors for AA7049: Mixture vs. complexation

In this work new green corrosion inhibitors based on the synthesized cerium-cysteine complex on AA7049 aluminum alloy were analyzed and compared to the mixture of CeCl3 and cysteine in 0.1 M NaCl. The complex structures were confirmed by FTIR, NMR and Elemental Analysis. It was shown that cerium was present in two oxidation states, CeIII and CeIV, when the mixture was analyzed, while there was only a CeIV oxidation state in the cerium-cysteine complex. The mechanisms of inhibitory action of the joint effect of CeCl3 and cysteine vs. their complex were proposed and analyzed in more detail.

Automated summary

This study analyzed and compared new green corrosion inhibitors based on the synthesized cerium-cysteine complex on AA7049 aluminum alloy and the mixture of CeCl3 and cysteine in 0.1 M NaCl. The structures of the complexes were confirmed, and the impact of different oxidation states on the inhibitory action mechanism of the corrosion inhibitors was proposed and analyzed.