Characterization of zeolite-supported Pt-Cu bimetallic catalyst by xenon-129 NMR and EXAFS

Journal Article · Tue Dec 31 23:00:00 EST 1991 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90197-P· OSTI ID:7227250

Ahn, D H; Woo, S I ^[1]; Lee, J S ^[2]; Nomura, M ^[3]; Sachtler, W M.H.; Moretti, G ^[4]; Ryoo, R ^[5]

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1. Korea Advanced Inst. of Science and Technology, Seoul, (Korea)
2. Pohang Inst. of Science and Technology (Korea)
3. National Lab. for High Energy Physics, Ibaraki (Japan)
4. Northwestern Univ., Evanston, Illinois (United States)
5. Korea Advanced Inst. of Science and Technology, Taejon (Korea)

Samples of platinum supported on NaY zeolite (Pt/NaY), Cu/NaY, and bimetallic Pt-Cu/NaY have been prepared by using a scheme that consists of ion exchange of the metalammine cations, activation in flowing O{sub 2}, and subsequent reduction in H{sub 2}. These samples have been characterized by {sup 129}Xe NMR and extended X-ray absorption fine structure (EXAFS). The chemical shift in {sup 129}Xe NMR of the xenon adsorbed on Pt-Cu/NaY has been found to be significantly lower than that on Pt/NaY with the same Pt content under the same experimental conditions, and therefore bimetallic Pt-Cu clusters are formed in supercages of NaY zeolite in both the cases of a sequential clustering method and a simultaneous ion exchange preparation method. The peak intensities at Pt-Pt coordination distance in the Fourier transforms of EXAFS spectra for Pt/NaY and Pt-Cu/NaY are very similar, which indicates that the reduction of Cu precursor has resulted in no appreciable changes in the Pt-Pt coordination structure of the Pt cluster. It thus appears, from these results, that during the reduction of Cu precursor the bimetallic Pt-Cu clusters are formed with a model of a Cu covering on Pt clusters in the supercage of NaY zeolite.

• OSTI ID: 7227250
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 133:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ALLOYS
BIMETALS
CATALYST SUPPORTS
CATALYSTS
CHEMICAL ACTIVATION
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHEMICAL SHIFT
COPPER
COPPER ALLOYS
DAYS LIVING RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
FOURIER TRANSFORMATION
INORGANIC ION EXCHANGERS
INTEGRAL TRANSFORMATIONS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ION EXCHANGE
ION EXCHANGE MATERIALS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAGNETIC RESONANCE
MATERIALS
METALS
MINERALS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
PLATINUM
PLATINUM ALLOYS
PLATINUM METAL ALLOYS
PLATINUM METALS
RADIOISOTOPES
REDUCTION
RESONANCE
SILICATE MINERALS
SPECTROSCOPY
STABLE ISOTOPES
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
TRANSFORMATIONS
TRANSITION ELEMENTS
X-RAY SPECTROSCOPY
XENON 129
XENON ISOTOPES
ZEOLITES