Abstract
Alloy particles were detected by XRD in bimetallic catalysts, made from physical mixtures of powders comprising distinct metal-support combinations (e.g., Pd on alumina and Rh on ceria-zirconia), following high-temperature redox aging. The morphology of the catalysts was examined by TEM, and the compositional structure of some of the alloy particles was determined. Two different effects of the redistribution of metals on oxygen-storage capacity were identified, one due to Pd enrichment of the surface of Pd-Rh alloy particles and the other due to loss of contact between metal and ceria-zirconia.
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References
H.-W. Jen, G.W. Graham, W. Chun, R.W. McCabe, J.-P. Cuif, S. Deutsch and O. Touret, Catal. Today 50 (1999) 309.
G.W. Graham, H.-W. Jen, R.W. McCabe, A.M. Straccia and L.P. Haack, Catal. Lett. 67 (2000) 99.
H.C. Yao, S. Japar and M. Shelef, J. Catal. 48 (1977) 111.
H.C. Yao, H.K. Stepien and H.S. Gandhi, J. Catal. 61 (1980) 547.
Y.-F. Yu-Yao and J.T. Kummer, J. Catal. 106 (1987) 307.
J.S. Hepburn et al., Paper No. 941058, Society of Automotive Engineers, Warrendale, PA (1994).
JCPDS files for Pt (04-0802), Pd (46-1043), Rh (05-0685), ceriazirconia (38-1439), alumina (δ: 04-0877, θ: 11-0517), PdO (41-1107), Rh2O3 (41-541) and PdRhO2 (27-1325).
17th North American Catalysis Meeting, “Modification of Oxygen-Storage-Capacities of Aged Pd/Ce0.63Zr0.37O2 and Rh/Ce0.63Zr0.37O2 Model Catalysts”, Hung-Wen Jen, George W. Graham and Robert W. McCabe (unpublished).
H.-W. Jen (unpublished).
W.G. Moffat, The Handbook of Binary Phase Diagrams, vol. 5 (Genium Publishing Corporation, New York, 1984).
G.W. Graham, H.-W. Jen, W. Chun and R.W. McCabe, J. Catal. 182 (1999) 228.
P. Wynblatt and N.A. Gjostein, in: Progress in Solid State Chemistry, Vol. 9, eds. J.O. McCaldin and G. Somorjai (Pergamon Press, 1975) ch. 2.
Z. Hu, F.M. Allen, C.Z. Wan, R.M. Heck, J.J. Steger, R.E. Lakis and C.E. Lyman, J. Catal. 174 (1998) 13.
G.W. Graham, T. Potter, R.J. Baird, H.S. Gandhi and M. Shelef, J. Vac. Sci. Technol. A4 (1986) 1613.
R.J. Baird, G.W. Graham and W.H. Weber, Oxid. Met. 29 (1988) 435.
W.-J. Shen, A. Kobayashi, Y. Ichihashi, Y. Matsumura and M. Haruta, Catal. Lett. 73 (2001) 161.
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Graham, G., Sun, H., Jen, HW. et al. Aging-Induced Metal Redistribution in Bimetallic Catalysts. Catalysis Letters 81, 1–7 (2002). https://doi.org/10.1023/A:1016051821097
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DOI: https://doi.org/10.1023/A:1016051821097