Hydrogen in aluminum during alkaline corrosion
| Title | Hydrogen in aluminum during alkaline corrosion |
| Publication Type | Journal Article |
| Year of Publication | 2010 |
| Authors | Adhikari S, Ai JH, Hebert KR, Ho KM, Wang CZ |
| Journal Title | Electrochimica Acta |
| Volume | 55 |
| Pages | 5326-5331 |
| Date Published | 7/30 |
| ISBN Number | 0013-4686 |
| Accession Number | ISI:000280018800007 |
| Keywords | adsorption, aluminum, corrosion, diffusion, electrode, HYDRIDE, hydrogen absorption, hydrogen chemical potential, hydrogen diffusion, metals, palladium, permeation, PH, system |
| Abstract | The thermodynamic state of hydrogen in aluminum during alkaline corrosion was investigated, using a two-compartment hydrogen permeation cell with an Al/Pd bilayer membrane. The open-circuit potential of the Pd layer in a pH 7.0 buffer solution was monitored to sense the hydrogen chemical potential, pH. At pH 12.5-13.5, the measurements established a minimum pH of 0.55 eV relative to the ideal gas reference, equivalent to a H-2 gas pressure of 5.7 GPa. Statistical mechanics calculations show that vacancy-hydrogen defects are stable in Al at this condition. A dissolution mechanism was proposed in which H at very high pH is produced by oxidation of interfacial aluminum hydride. The mechanism explains the observed rapid accumulation of H in the metal by extensive formation of vacancy-hydrogen defects. (C) 2010 Elsevier Ltd. All rights reserved. |
| URL | <Go to ISI>://000280018800007 |
| DOI | Doi 10.1016/J.Electacta.2010.04.076 |
