Epitaxial growth mechanism of heterogeneous catalytic oxidation of Mn(II) on manganite under oxic conditions
Journal Article
·
· Chemical Geology
- Huazhong Agricultural Univ., Hubei Province (China); Univ of Connecticut
- Huazhong Agricultural Univ., Hubei Province (China)
- Univ. of Connecticut, Storrs, CT (United States)
Manganese oxides are ubiquitous in soils and sediments, and their formation and transformation processes affect the migration and transformation of heavy metals and organic pollutants. Most previous work has been focused the oxidation of Mn(II) on Mn(IV) oxide surface, but it remains poorly understood how Mn(II) interacts with manganite under oxic conditions. Here, the interactions between manganite and dissolved Mn(II) within pH 5.0–9.0 under oxic conditions were systematically studied. The results indicated that adsorbed Mn(II) was directly oxidized to manganite on the surface, and the oxidation rate increased with increasing pH and oxygen partial pressure. Electrons are likely transferred in bulk manganite during the oxidation process of Mn(II). Although manganite induced Mn(II) oxidation and the epitaxial growth of bulk particles, there was no obvious change in mineral phase. Dissolved oxygen accelerated the growth of manganite in Mn(II) solution. Compared with the absence of manganite, the presence of manganite inhibited the formation of hausmannite from Mn(II) oxidation by oxygen in air. Furthermore, this study reveals the catalytic oxidation process and mechanism of Mn(II) on manganite surface, and improves the understanding of manganite crystal growth in supergene environments.
- Research Organization:
- Univ. of Connecticut, Storrs, CT (United States)
- Sponsoring Organization:
- Fok Ying Tong Education Foundation; National Key Research and Development Program of China; National Natural Science Foundation of China; USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division
- Grant/Contract Number:
- FG02-86ER13622
- OSTI ID:
- 1776498
- Alternate ID(s):
- OSTI ID: 1838008
OSTI ID: 1691844
- Journal Information:
- Chemical Geology, Journal Name: Chemical Geology Vol. 547; ISSN 0009-2541
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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