Properties of supported Pd-Ni catalysts prepared by coexchange and by organometallic chemistry

Journal Article · Wed Dec 01 04:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1346· OSTI ID:5183787

Faudon, J F; Bergeret, G; Moraweck, B; Clugnet, G; Nicot, C; Renouprez, A ^[1]; Senocq, F ^[2]

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1. Institut de Recherches sur la Catalyse, CNRS, Villeurbanne Cedex (France)
2. Laboratoire des Materiaux en Couches Minces, Toulouse Cedex (France)

Bimetallic catalysts are widely used in catalytic reforming and in fine chemistry. Silica-supported Pd-Ni bimetallic catalysts were prepared either by coexchange or via surface organometallic chemistry. In this later case, Ni(C[sub 5]H[sub 5])[sub 2] was allowed to react with a reduced Pd/SiO[sub 2]. The temperature of formation of the alloy was determined by in situ X-ray diffraction performed under flowing H[sub 2] and the atomic order was determined by EXAFS. It is shown that the alloy is already formed at 620 K with organometallic precursors, whereas 840 K is necessary with coexchanged solids. A comparison between the X-ray methods and a careful analysis of the particle composition by EDX-STEM shows that the organometallic route leads to nearly homogeneous alloys. Alloy formation also occurs with coexchanged precursors; however, nickel in strong interaction with the support and unalloyed palladium are also observed. 18 refs., 10 figs., 5 tabs.

• OSTI ID: 5183787
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 144:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALLOYS
CATALYST SUPPORTS
CHEMICAL PREPARATION
COHERENT SCATTERING
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
METALS
MICROSCOPY
NICKEL
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PALLADIUM ALLOYS
PLATINUM METAL ALLOYS
SCATTERING
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY