Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-25T15:47:27.895Z Has data issue: false hasContentIssue false
  • English
  • Français

Redox Processes in Polynary Copper Oxides and Copper Oxide / Mesoporous Silica Composites

Published online by Cambridge University Press:  16 February 2011

A. Reller ,
S. Ebbinghaus ,
R. Köhn ,
M. Fröba ,
U. Sazama  and
P. Fortunato
A. Reller
Affiliation:
Institute of Inorganic and Applied Chemistry, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany; [email protected]
S. Ebbinghaus
Affiliation:
Institute of Inorganic and Applied Chemistry, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany; [email protected]
R. Köhn
Affiliation:
Institute of Inorganic and Applied Chemistry, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany; [email protected]
M. Fröba
Affiliation:
Institute of Inorganic and Applied Chemistry, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany; [email protected]
U. Sazama
Affiliation:
Institute of Inorganic and Applied Chemistry, University of Hamburg, Martin-Luther-King-Pl. 6, 20146 Hamburg, Germany; [email protected]
P. Fortunato
Affiliation:
Institute of Inorganic Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 ZUrich, Switzerland
Get access

Abstract

Dynamic redox processes in different complex copper oxides and oxide / mesoporous silica composites are characterized. In the spinel-type CuxMn3.xO4 the atomic and electronic structures are described with respect to the reversible process Cu2+ + Mn3+ ⇒ Cu3+ + Mn4+, the crucial dynamic equilibrium for the catalytic oxidation of CO to CO2 at ambient temperatures. A comparison with the perovskite-type LaCu1-xMnxO3-δ is presented. In the K2NiF4-type La2-xSrxCu1-yRuyO4-δ the electronic structure is characterized with respect to the equilibrium Cu2+ + Ru5+ ⇒ Cu3+ + Ru4+. Analogous redox processes are characterized in composite compounds made up of copper oxides inserted in mesoporous MCM-type silica. Due to their structural order in the nanoscopic range, the investigation of these materials required multiple, complementary characterization methods, i.e. X-ray diffractometry, thermal analysis, scanning and transmission electron microscopy, magnetic measurements, XPS, and particularly X-ray absorption spectroscopy (EXAFS / XANES) measurements.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 547: Symposium DD – Solid-State Chemistry of Inorganic Materials II , 1998 , 75
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Fortunato, P., Ph.D. thesis, University of Zürich, 1997.Google Scholar
[2] Fortunato, P., Oswald, H.R. and Reller, A., Solid State Ionics 101-103, 85 (1997).Google Scholar
[3] Ebbinghaus, S., Ph.D. thesis, University of Hamburg, 1998.Google Scholar
[4] Ebbinghaus, S., Reller, A., Solid State lonics 101-103, 1369 (1997).Google Scholar
[5] Ebbinghaus, S., Fröba, M., Reller, A., J. Phys. Chem. B 101, 9909 (1997).Google Scholar
[6] Fröba, M., Köhn, R., Bouffaud, G., Richard, O., van Tendeloo, G., Chem. Mater. (1998), submitted.Google Scholar
[7] Bednorz, J.G. and MIiller, K.A., Z. Phys. B64, 189 (1986).Google Scholar
[8] Maeno, Y., Hashimoto, H., Yoshida, K., Nishizaki, S., Fujita, T., Bednorz, J.G. and Lichtenberg, F., Nature 372, 532 (1994).Google Scholar
[9] Dussarrat, C., Grasset, F., Bontchev, R., Darriet, J., J. of Alloys and Compounds 233, 15 (1996).Google Scholar
[10] Grasset, F., Dussarrat, C., Darriet, J., J. Mater.Chem. 7, 1911 (1997)Google Scholar
[11] Dussarrat, C., Fompeyrine, J., Darriet, J., Eur. J. Solid State Chem. 32, 3 (1995)Google Scholar