Mechanism of hydrogen formation during the corrosion of Mg17Al12
Previous investigations (DFT calculations) showed that hydrogen atoms adsorption and H2 desorption can occur on MgO and Al2O3 and that H atoms can diffuse on Mg and Al surfaces. However, these three simultaneous actions, i.e. H adsorption, H diffusion and H2 desorption, have not been experimentally...
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| Format: | Article |
| Language: | English |
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Elsevier
2020-10-01
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| Series: | Electrochemistry Communications |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1388248120301648 |
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| author | S. Al Bacha A. Desmedt M. Zakhour M. Nakhl J.-L. Bobet |
| author_facet | S. Al Bacha A. Desmedt M. Zakhour M. Nakhl J.-L. Bobet |
| author_sort | S. Al Bacha |
| collection | DOAJ |
| description | Previous investigations (DFT calculations) showed that hydrogen atoms adsorption and H2 desorption can occur on MgO and Al2O3 and that H atoms can diffuse on Mg and Al surfaces. However, these three simultaneous actions, i.e. H adsorption, H diffusion and H2 desorption, have not been experimentally proved. In this paper, we propose a mechanism of formation of H2 during the corrosion of an intermetallic compound Mg17Al12 in 3.5 wt.% NaCl aqueous solution based on in situ Raman spectroscopy analysis. We found that, through the passivation zone (e.g. E varying from the open circuit potential (OCP) to +100 mV/OCP), the oxide layer is destroyed in favor of the appearance of Mg and H atoms. Moreover, the formed H atoms are adsorbed on the oxide surface and then diffuse on either the oxide surface or the unreacted metal surface where they recombine forming H2. In situ Raman measurements during anodic polarization experimentally prove, for the first time, the formation of a reaction intermediate which weakens the H–H bond. The obtained results explain the mechanism of hydrogen production under anodic polarization of the intermetallic compound at normal conditions of temperature and pressure. |
| first_indexed | 2024-12-10T22:20:56Z |
| format | Article |
| id | doaj.art-126c0045028542308eb9032b93a6f64e |
| institution | Directory Open Access Journal |
| issn | 1388-2481 |
| language | English |
| last_indexed | 2024-12-10T22:20:56Z |
| publishDate | 2020-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Electrochemistry Communications |
| spelling | doaj.art-126c0045028542308eb9032b93a6f64e2022-12-22T01:31:18ZengElsevierElectrochemistry Communications1388-24812020-10-01119106813Mechanism of hydrogen formation during the corrosion of Mg17Al12S. Al Bacha0A. Desmedt1M. Zakhour2M. Nakhl3J.-L. Bobet4LCPM/PR2N, Lebanese University, 90656 Jdeidet El Metn, Lebanon; ICMCB – CNRS, University of Bordeaux, UPR 9048, F-33600 Pessac, France; Corresponding author at: LCPM/PR2N, Lebanese University, 90656 Jdeidet El Metn, Lebanon and ICMCB, University of Bordeaux, 87 av. Dr. Schweitzer, 33600 Pessac, France.ISM – CNRS, University of Bordeaux, UMR 5255, F-33405 Talence, FranceLCPM/PR2N, Lebanese University, 90656 Jdeidet El Metn, LebanonLCPM/PR2N, Lebanese University, 90656 Jdeidet El Metn, LebanonICMCB – CNRS, University of Bordeaux, UPR 9048, F-33600 Pessac, FrancePrevious investigations (DFT calculations) showed that hydrogen atoms adsorption and H2 desorption can occur on MgO and Al2O3 and that H atoms can diffuse on Mg and Al surfaces. However, these three simultaneous actions, i.e. H adsorption, H diffusion and H2 desorption, have not been experimentally proved. In this paper, we propose a mechanism of formation of H2 during the corrosion of an intermetallic compound Mg17Al12 in 3.5 wt.% NaCl aqueous solution based on in situ Raman spectroscopy analysis. We found that, through the passivation zone (e.g. E varying from the open circuit potential (OCP) to +100 mV/OCP), the oxide layer is destroyed in favor of the appearance of Mg and H atoms. Moreover, the formed H atoms are adsorbed on the oxide surface and then diffuse on either the oxide surface or the unreacted metal surface where they recombine forming H2. In situ Raman measurements during anodic polarization experimentally prove, for the first time, the formation of a reaction intermediate which weakens the H–H bond. The obtained results explain the mechanism of hydrogen production under anodic polarization of the intermetallic compound at normal conditions of temperature and pressure.http://www.sciencedirect.com/science/article/pii/S1388248120301648HydrogenMonovalent MgCorrosionMg17Al12RamanMg+/MgH+ |
| spellingShingle | S. Al Bacha A. Desmedt M. Zakhour M. Nakhl J.-L. Bobet Mechanism of hydrogen formation during the corrosion of Mg17Al12 Electrochemistry Communications Hydrogen Monovalent Mg Corrosion Mg17Al12 Raman Mg+/MgH+ |
| title | Mechanism of hydrogen formation during the corrosion of Mg17Al12 |
| title_full | Mechanism of hydrogen formation during the corrosion of Mg17Al12 |
| title_fullStr | Mechanism of hydrogen formation during the corrosion of Mg17Al12 |
| title_full_unstemmed | Mechanism of hydrogen formation during the corrosion of Mg17Al12 |
| title_short | Mechanism of hydrogen formation during the corrosion of Mg17Al12 |
| title_sort | mechanism of hydrogen formation during the corrosion of mg17al12 |
| topic | Hydrogen Monovalent Mg Corrosion Mg17Al12 Raman Mg+/MgH+ |
| url | http://www.sciencedirect.com/science/article/pii/S1388248120301648 |
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