resumo
In our recent work (Hoche et al. 2016) we proposed that non-faradaic dissolution of Fe impurities and/or iron containing phases with subsequent re-deposition of thin film of pure ("in statu nascendi") iron enlarges cathodically active sites at the surface of corroding magnesium. The effect drastically accelerates corrosion of impurity containing Mg. In the present work we assume that if Fe re-deposition is prevented, the area of cathodic sites can be drastically decreased and hence corrosion of Mg can be suppressed. In this proof of concept work we use strong Fe3+ completing agents in order to remove dissolved iron cations from corrosion sites and prevent iron re-deposition. All used iron complexing agents efficiently lowered the corrosion rate of Mg. Direct correlation of complex stability with its inhibiting efficiency was established. It was shown that cyanide, salicylate, oxalate, methylsalicylate and thiocyanate efficiently reduce hydrogen evolution and suppress critical dark area formation. (c) 2015 Elsevier B.V. All rights reserved.
palavras-chave
ENHANCED CATALYTIC-ACTIVITY; HYDROGEN EVOLUTION; COMPLEXES; ALLOY; MG; DISSOLUTION; TETRAPHENYLPORPHYRIN; ELECTROLYTE; MECHANISM; SURFACES
categoria
Electrochemistry
autores
Lamaka, SV; Hoche, D; Petrauskas, RP; Blawert, C; Zheludkevich, ML
nossos autores
Mikhail Zheludkevich
Investigador Principal ConvidadoGrupos
agradecimentos
Dr. S.V. Lamaka acknowledges the financial support of Alexander von Humboldt Foundation via Experienced Researcher Grant. R.P. Petrauskas thanks Erasmus + Programme, grant no.2015-1-LT01-KA103-013105.