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

Title: Reactivity of Fe(III) in the Octahedral Sheet of Natural and Synthetic Fe-phyllosilicates.

Abstract

Abstract not provided.

Authors:
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1377719
Report Number(s):
SAND2016-7923C
646637
DOE Contract Number:
AC04-94AL85000
Resource Type:
Conference
Resource Relation:
Conference: Proposed for presentation at the APS User Meeting held May 9-11, 2016 in Chicago, IL.
Country of Publication:
United States
Language:
English

Citation Formats

Ilgen, Anastasia Gennadyevna. Reactivity of Fe(III) in the Octahedral Sheet of Natural and Synthetic Fe-phyllosilicates.. United States: N. p., 2016. Web.
Ilgen, Anastasia Gennadyevna. Reactivity of Fe(III) in the Octahedral Sheet of Natural and Synthetic Fe-phyllosilicates.. United States.
Ilgen, Anastasia Gennadyevna. 2016. "Reactivity of Fe(III) in the Octahedral Sheet of Natural and Synthetic Fe-phyllosilicates.". United States. doi:. https://www.osti.gov/servlets/purl/1377719.
@article{osti_1377719,
title = {Reactivity of Fe(III) in the Octahedral Sheet of Natural and Synthetic Fe-phyllosilicates.},
author = {Ilgen, Anastasia Gennadyevna},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 8
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • Abstract not provided.
  • No abstract prepared.
  • Cryptomelane is known to be a manganese oxide octahedral molecular sieve having a well-defined 2 x 2 tunnel structure (OMS-2) with K{sup +} situated in tunnel positions. The mobility and reactivity of oxygen in such tunnel structures with different tunnel cations were studied by means of temperature-programmed desorption (TPD) and reduction with H{sub 2} and CO{sub 2}. Oxygen released during TPD from OMS-2 materials is significantly greater in amount than that from OMS-1 (3x3 tunnel structure), although the relative populations of oxygen from different desorption temperature regimes are much the same as that of OMS-1. Oxygen species corresponding to low-temperature,more » medium-temperature, and high-temperature TPD peaks can be assigned to weakly bound chemisorbed dioxygen, oxygen atoms bound to lower valent Mn ions, and those bound to Mn{sup 4+} ions in the framework, just as is the case for OMS-1. Among the different tunnel cations, Cu{sup 2+} exhibits a distinct feature of having more available oxygen species that are reactive at low temperature. The availability of oxygen in Cu{sup 2+} exhibits a distinct feature of having more available oxygen species that are reactive at low temperature. The availability of oxygen in Cu{sup 2+}-doped OMS-2 was also studied by frontal reduction at 563 K with CO/He. The amount of oxygen depleted during frontal reduction is close to that during TPR by CO/He. The depleted Cu{sup 2+} hollandite can be reoxidized to about 85% recovery of oxygen by oxygen pulse reactions. X-ray diffraction patterns show that 2 x 2 tunnel structure remains intact after heating in an oxygen-free gas stream up to 778 K, but collapses after reduction in CO at 563 K. These studies emphasize the importance of pretreatment of OMS materials prior to use in catalysis or adsorption.« less
  • Manganese K-edge X-ray absorption spectra are used to examine the average oxidation state and local structure of new synthetic manganese oxide photocatalysts, including the materials known as octahedral molecular sieves. The structures of these materials are compared to the natural minerals cryptomelane and todorokite.