Free-Energy Landscape of the Dissolution of Gibbsite at High pH.
J Phys Chem Lett
; 9(7): 1809-1814, 2018 Apr 05.
Article
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| MEDLINE
| ID: mdl-29575896
The individual elementary reactions involved in the dissolution of a solid into solution remain mostly speculative due to a lack of direct experimental probes. In this regard, we have applied atomistic simulations to map the free-energy landscape of the dissolution of gibbsite from a step edge as a model of metal hydroxide dissolution. The overall reaction combines kink formation and kink propagation. Two individual reactions were found to be rate-limiting for kink formation, that is, the displacement of Al from a step site to a ledge adatom site and its detachment from ledge/terrace adatom sites into the solution. As a result, a pool of mobile and labile adsorbed species, or adatoms, exists before the release of Al into solution. Because of the quasi-hexagonal symmetry of gibbsite, kink site propagation can occur in multiple directions. Overall, our results will enable the development of microscopic mechanistic models of metal oxide dissolution.
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Colección:
01-internacional
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MEDLINE
Idioma:
En
Revista:
J Phys Chem Lett
Año:
2018
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos