Abstract
A structural study of CuO supported on a CeO2–TiO2 system was undertaken using X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) techniques. The results of XRD revealed the presence of only two phases, TiO2 anatase and CeO2 cerianite. A trend towards smaller TiO2 crystallites was observed when cerium content increased. When the amount of cerium increased, Ti K-edge XANES analysis showed an increasing distortion of Ti sites. The results of Ce LIII-edge EXAFS showed that Ce atoms are coordinated by eight oxygen atoms at 2.32 Å. For the sample containing a small amount of cerium, the EXAFS analysis indicated that the local structure around Ce atoms was highly distorted. The catalysts presented quite different Cu K-edge XANES spectra compared to the spectra of the CuO and Cu2O reference compounds. The Cu–O mean bond length was close to that of the CuO and the Cu atoms in the catalysts are surrounded by approximately four oxygen atoms in their first shell. Copper supported on the ceria-modified titania support catalysts displayed a better performance in the methanol dehydrogenation when compared to copper supported only on titania or on ceria.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
N. Takezawa and N. Iwasa, Catal. Today 36 (1997) 45.
J.P. Breen and J.R.H. Ross, Catal. Today 51 (1999) 521.
G. Dong, J. Wang, Y. Gao and S. Chen, Catal. Lett. 58 (1999) 37.
P.-O. Larsson and A. Andersson, Appl. Catal. B 24 (2000) 175.
P.M. Kumar, S. Badrinarayanan and M. Sastry, Thin Solid Films 358 (2000) 122.
A. Music, J. Batista and J. Levec, Appl. Catal. A 165 (2000) 115.
L. Domokos, T. Katona and Á. Molnár, Catal. Lett. 40 (1996) 215.
J.L. Davis and M.A. Barteu, Surf. Sci. 235 (1990) 235.
P.-O. Larsson and A. Andersson, J. Catal. 179 (1998) 72.
A. Trovarelli, F. Zamar, J. Lorca, C. Leitenburg and J.T. Kiss, J. Catal. 169 (1997) 490.
G. Balducci, J. Kaspar, P. Fornasiero, M. Graziani, M.S. Islam and J.D. Gale, J. Phys. Chem. B 101 (1997) 1750.
C.J. Brinker and G. W. Scherrer, Sol–Gel Science: the Physics and Chemistry of Sol–Gel Processing (Academic Press, New York, 1993).
R.D. Gonzalez, T. Lopez and R. Gomez, Catal. Today 35 (1997) 293.
A. Martínez-Arias, M. Fernández-García, J. Soria and J.C. Conesa, J. Catal. 182 (1999) 367.
B.E. Warren, X-Ray Diffraction (Addison-Wesley, Reading, MA, 1969) p. 253.
A. Michalowicz, in: Logiciels pour la Chimie (Société Française de Chimie, Paris, 1991) p. 102.
S.S. Hasnain, ed. in: X-Ray Absorption Fine Structure: Proc. of the VI Int. Conf. on X-Ray Absorption Fine Structures (Ellis Horwood, New York, 1991) p. 752.
Z.Y. Wu, G. Ouvrard, P. Gressier and C.R. Natoli, Phys. Rev. B 55 (1997) 10382.
L.A. Grunes, Phys. Rev. B 27 (1983) 2111.
V. Luca, S. Djajanti and R.F. Howe, J. Phys. Chem. B 102 (1998) 10650.
M.C. Ruiz-López and A. Muñoz-Páez, J. Phys. 3 (1991) 8981.
P. Ghigna, G. Spinolo, M. Scavini, A. Tamburini and A.V. Chadwick, Physica C 253 (1995) 147.
Y. Takahashi, H. Shimizu, A. Usui, H. Kagi and M. Nomura, Geochim. Cosmoch. Act. 64 (2000) 2929.
Y. Okamoto, T. Kubota, H. Gotoh, Y. Ohto, H. Aritani, T. Tanaka and S. Yoshida, J. Chem. Soc. Faraday Trans. 94 (1998) 3743.
W. Liu and M. Flytzani-Stephanopoulos, J. Catal. 153 (1995) 304.
W. Liu and M. Flytzani-Stephanopoulos, J. Catal. 153 (1995) 317.
M.-F. Luo, Y.-J. Zhong, X.-X. Yuan and X.-M. Zheng, Appl. Catal. B 162 (1997) 121.
B. Ernst, L. Hilaire and A. Kiennemann, Catal. Today 50 (1999) 413.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Francisco, M., Mastelaro, V., Florentino, A. et al. Structural Study of Copper Oxide Supported on a Ceria-Modified Titania Catalyst System. Topics in Catalysis 18, 105–111 (2002). https://doi.org/10.1023/A:1013845314192
Issue Date:
DOI: https://doi.org/10.1023/A:1013845314192