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Title: Surface sites on spinel-type and corundum-type metal oxide powders

Abstract

The surface sites on isostructural metal oxides containing Al{sup 3+}, Fe{sup 3+}, and Cr{sup 3+} have been investigated by IR spectroscopy. The IR spectra of surface hydroxy groups and of pyridine coordinated on Lewis acidic surface cationic sites on the defective spinel-type sesquioxides {gamma}-Al{sub 2}O{sub 3}, {theta}-Al{sub 2}O{sub 3}, and {gamma}-Fe{sub 2}O{sub 3}, on the spinels MgAl{sub 2}O{sub 4}, MgFe{sub 2}O{sub 4}, MgCr{sub 2}O{sub 4}, ZnAl{sub 2}O{sub 4}, ZnFe{sub 2}O{sub 4}, and ZnCr{sub 2}O{sub 4}, as well as on the corundum-type sesquioxides {alpha}-Al{sub 2}O{sub 3}, {alpha}-Fe{sub 2}O{sub 3}, and {alpha}-Cr{sub 2}O{sub 3}, have been compared. Some Co{sup 2+} and Ni{sup 2+} spinel-type compounds have also been considered. An extension of the criteria previously proposed for the identification of the surface sites on aluminum-based materials to ferrites and chromites is suggested. The OH stretchings of surface hydroxy groups are indicative of the nature and the coordination of the cations to which they are bonded. Pyridine species bonded to tetrahedrally- and octahedrally-coordinated trivalent cations are well distinguishable on aluminates, while the distiction is more difficult for ferrites. 41 refs., 9 figs., 3 tabs.

Authors:
; ;  [1];  [2]
  1. Universita de Genova (Italy)
  2. Northeastern Univ., Boston, MA (United States)
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
603044
Resource Type:
Journal Article
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 9; Journal Issue: 6; Other Information: PBD: Jun 1993
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SURFACE PROPERTIES; ALUMINIUM OXIDES; IRON OXIDES; CHROMIUM OXIDES; INFRARED SPECTRA; POWDERS; PYRIDINE; SPINELS; BOND LENGTHS

Citation Formats

Busca, G, Lorenzelli, V, Ramis, G, Northeastern Univ., Boston, MA, and Willey, R J. Surface sites on spinel-type and corundum-type metal oxide powders. United States: N. p., 1993. Web. doi:10.1021/la00030a012.
Busca, G, Lorenzelli, V, Ramis, G, Northeastern Univ., Boston, MA, & Willey, R J. Surface sites on spinel-type and corundum-type metal oxide powders. United States. https://doi.org/10.1021/la00030a012
Busca, G, Lorenzelli, V, Ramis, G, Northeastern Univ., Boston, MA, and Willey, R J. Tue . "Surface sites on spinel-type and corundum-type metal oxide powders". United States. https://doi.org/10.1021/la00030a012.
@article{osti_603044,
title = {Surface sites on spinel-type and corundum-type metal oxide powders},
author = {Busca, G and Lorenzelli, V and Ramis, G and Northeastern Univ., Boston, MA and Willey, R J},
abstractNote = {The surface sites on isostructural metal oxides containing Al{sup 3+}, Fe{sup 3+}, and Cr{sup 3+} have been investigated by IR spectroscopy. The IR spectra of surface hydroxy groups and of pyridine coordinated on Lewis acidic surface cationic sites on the defective spinel-type sesquioxides {gamma}-Al{sub 2}O{sub 3}, {theta}-Al{sub 2}O{sub 3}, and {gamma}-Fe{sub 2}O{sub 3}, on the spinels MgAl{sub 2}O{sub 4}, MgFe{sub 2}O{sub 4}, MgCr{sub 2}O{sub 4}, ZnAl{sub 2}O{sub 4}, ZnFe{sub 2}O{sub 4}, and ZnCr{sub 2}O{sub 4}, as well as on the corundum-type sesquioxides {alpha}-Al{sub 2}O{sub 3}, {alpha}-Fe{sub 2}O{sub 3}, and {alpha}-Cr{sub 2}O{sub 3}, have been compared. Some Co{sup 2+} and Ni{sup 2+} spinel-type compounds have also been considered. An extension of the criteria previously proposed for the identification of the surface sites on aluminum-based materials to ferrites and chromites is suggested. The OH stretchings of surface hydroxy groups are indicative of the nature and the coordination of the cations to which they are bonded. Pyridine species bonded to tetrahedrally- and octahedrally-coordinated trivalent cations are well distinguishable on aluminates, while the distiction is more difficult for ferrites. 41 refs., 9 figs., 3 tabs.},
doi = {10.1021/la00030a012},
url = {https://www.osti.gov/biblio/603044}, journal = {Langmuir},
number = 6,
volume = 9,
place = {United States},
year = {1993},
month = {6}
}