Structural study of copper oxide supported on a ceria-modified titania catalyst system


Autoria(s): Francisco, M. S. P.; Mastelaro, V. R.; Florentino, A. O.; Bazin, D.
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

27/05/2014

27/05/2014

01/01/2002

Resumo

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. © 2002 Plenum Publishing Corporation.

Formato

105-111

Identificador

http://dx.doi.org/10.1023/A:1013845314192

Topics in Catalysis, v. 18, n. 1-2, p. 105-111, 2002.

1022-5528

http://hdl.handle.net/11449/132291

10.1023/A:1013845314192

WOS:000175611400018

2-s2.0-0242443736

Idioma(s)

eng

Publicador

Kluwer Academic/plenum Publ

Relação

Topics in Catalysis

Direitos

closedAccess

Palavras-Chave #Catalysts #CuO-CeO2-TiO2 #Structure #XAS #XRD #CeO2-TiO2 #Cerium content #Cu atoms #Cu K-edge #EXAFS #Local structure #Methanol dehydrogenation #Oxygen atom #Reference compounds #Structural studies #TiO2 anatase #Titania #Titania catalysts #Titania supports #XANES analysis #XANES spectra #Cerium #Cerium compounds #Copper #Methanol #Oxygen #Semiconducting bismuth compounds #Structure (composition) #Titanium dioxide #X ray absorption spectroscopy #X ray diffraction #Atoms
Tipo

info:eu-repo/semantics/conferencePaper