skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Free-Energy Landscape of the Dissolution of Gibbsite at High pH

Abstract

The individual elementary reactions involved in the dissolution of a solid into solution remain mostly speculative due to a lack of suitable, 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 site formation and kink site propagation. Two individual reactions were found to be rate-limiting for kink site 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 Al 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, the simulation results will enable the development of microscopic mechanistic models of metal oxide dissolution.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [1]
  1. Physical Sciences Division, Physical &, Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
  2. Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Energy Frontier Research Centers (EFRC) (United States). Interfacial Dynamics in Radioactive Environments and Materials (IDREAM)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1435889
Report Number(s):
PNNL-SA-132350
Journal ID: ISSN 1948-7185; KC0307010
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry Letters; Journal Volume: 9; Journal Issue: 7
Country of Publication:
United States
Language:
English

Citation Formats

Shen, Zhizhang, Kerisit, Sebastien N., Stack, Andrew G., and Rosso, Kevin M.. Free-Energy Landscape of the Dissolution of Gibbsite at High pH. United States: N. p., 2018. Web. doi:10.1021/acs.jpclett.8b00484.
Shen, Zhizhang, Kerisit, Sebastien N., Stack, Andrew G., & Rosso, Kevin M.. Free-Energy Landscape of the Dissolution of Gibbsite at High pH. United States. doi:10.1021/acs.jpclett.8b00484.
Shen, Zhizhang, Kerisit, Sebastien N., Stack, Andrew G., and Rosso, Kevin M.. Mon . "Free-Energy Landscape of the Dissolution of Gibbsite at High pH". United States. doi:10.1021/acs.jpclett.8b00484.
@article{osti_1435889,
title = {Free-Energy Landscape of the Dissolution of Gibbsite at High pH},
author = {Shen, Zhizhang and Kerisit, Sebastien N. and Stack, Andrew G. and Rosso, Kevin M.},
abstractNote = {The individual elementary reactions involved in the dissolution of a solid into solution remain mostly speculative due to a lack of suitable, 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 site formation and kink site propagation. Two individual reactions were found to be rate-limiting for kink site 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 Al 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, the simulation results will enable the development of microscopic mechanistic models of metal oxide dissolution.},
doi = {10.1021/acs.jpclett.8b00484},
journal = {Journal of Physical Chemistry Letters},
number = 7,
volume = 9,
place = {United States},
year = {Mon Mar 12 00:00:00 EDT 2018},
month = {Mon Mar 12 00:00:00 EDT 2018}
}