Structures and catalytic activity of Pt-Mo bimetallic ensembles derived from a new planar [PtMo[sub 6]O[sub 24]][sup 8 [minus]] heteropolyanion supported on Al[sub 2]O[sub 3] and SiO[sub 2]: I. Characterization of the supported [PtMo[sub 6]] catalysts

Journal Article · Mon Jun 01 04:00:00 EDT 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90040-O· OSTI ID:6938863

Liu, T; Asakura, K; Iwasawa, Y ^[1]; Lee, U ^[2]; Matsui, Y ^[3]

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1. Univ. of Tokyo, Hongo, Bunkyo-ku (Japan)
2. National Fisheries Univ. of Pusan, Nam-ku (Korea)
3. National Inst. for Research in Inorganic Materials, Tsukuba, Ibaraki (Japan)

Pt-Mo bimetallic ensembles active for ethene hydrogenation and ethane hydrogenolysis were prepared on silica and alumina using a new Anderson-type plane [PtMo[sub 6]O[sub 24]][sup 8 [minus]] heteropolyanion as a precursor. The structures of the supported bimetallic ensembles were determined by H[sub 2 [minus]]chemisorption, TEM (transmission electron microscopy), analytical TEM, XRD (X-ray diffraction), EXAFS (extended X-ray absorption fine structure), and XANES (X-ray absorption near edge structure). The heteropolyanion framework was maintained when it was supported on silica, but was broken when on alumina. After reduction at 773-823 K, dispersed particles with an eggshell structure (3.0 [plus minus] 0.5 nm) were formed on silica, where a small platinum cluster (ca. 1.0 nm) located in the center was covered with partially oxidized Mo-oxide layers. On alumina bimetallic clusters of 2.0 [plus minus] 0.5 nm were formed, and part of the molybdenum atoms were dispersed in low valence states on the Al[sub 2]O[sub 3] surface.

• OSTI ID: 6938863
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 135:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
36 MATERIALS SCIENCE
360602 -- Other Materials-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ALKANES
ALKENES
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BIMETALS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
CRYSTAL STRUCTURE
DEHYDROGENATION
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
ETHANE
ETHYLENE
HYDROCARBONS
HYDROGEN
HYDROGENATION
MICROSCOPY
MOLYBDATES
MOLYBDENUM ALLOYS
MOLYBDENUM COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM ALLOYS
PLATINUM COMPOUNDS
PLATINUM METAL ALLOYS
REFRACTORY METAL COMPOUNDS
SCATTERING
SEPARATION PROCESSES
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SPECTROSCOPY
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY