Mössbauer Effect Characterization of Silica Supported Rhodium-Iron Catalysts
Silica supported rhodium-iron catalysts were characterized with iron-57 Mössbauer spectra indicated that iron in the catalysts existed as iron(0) in the rhodium-iron alloy and iron(III) stabilized through the metal-support interaction. A part of iron(III) combined the rhodium-iron alloy and the silica as an anchor. The iron(III) to iron(0) ratio and Mössbauer effect parameters were found to depend on the iron to rhodium ratio in the catalysts. Their dependences correspond to the change of the catalytic properties of rhodium-iron catalysts with the iron content. A schematic model for the surface structure of the rhodium-iron catalysts is proposed. The Mössbauer spectra of rhodium-iron catalysts with various metal loading supported this model.
KeywordsIsomer Shift Metal Cluster Bimetallic Catalyst Silica Support Quadrupole Doublet
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- 1.M. Ichikawa, Chemtech., 680 (1982).Google Scholar
- T. Fukushima, Y. Ishii, Y. Onda, and M. Ichikawa, J. Chem. Soc., Chem. Commun, 1752 (1985).Google Scholar
- 3.M. Ichikawa, K. Sekizawa, K. Shikakura, and M. Kawai, J. Mol. Catal. 11, 167 (1982).Google Scholar
- 4.J. A. Dumesic, J. Phys. (Paris), Colloq., C6, 233 (1976).Google Scholar
- 5.R. L. Garten, in “Mössbauer Effect Methodology”, Vol. 10, I. J. Gruverman and C. W. Seidel, eds., Plenum Press, New York (1976).Google Scholar
- 6.L. Guczi, Catal. Rev. Sei. Eng. 23, 329 (1981).Google Scholar
- 7.M. L. Good, M. D. Patil, J. T. Donner, and C. P. Madhusudahan, in “Mössbauer Spectroscopy and Its Chemical Applications”, J. G. Stevens and G. K. Shenoy, eds., Am. Chem. Soc., Washington, D.C. (1981).Google Scholar
- 9.The program had been written originally in ALGOL by B. J. Duke and T. C. Gibb, J. Chem. Soc. (A), 1478 (1967), and it was rewritten by M. Takeda in Fortran.Google Scholar
- 15.M. Ichikawa, T. Fukushima, T. Yokoyama, N. Kosugi, and H. Kuroda, J. Chem. Soc., Chem. Commun., submitted for publication.Google Scholar