Characterization of supported palladium catalyst. III. Pd/Al sub 2 O sub 3

Journal Article · Wed Nov 01 04:00:00 EST 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90251-0· OSTI ID:6783224

Juszczyk, W; Karpinski, Z; Ratajczykowa, I; Stanasiuk, Z; Zielinski, J ^[1]; Sheu, L L; Sachtler, W M.H. ^[2]

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1. Institute of Physical Chemistry of the Polish Academy of Sciences, Warszawa, (Poland)
2. Northwestern Univ., Evanston, IL (USA)

In Part I of this series (W. Juszczyk et al., in Proceedings, 9th International Congress on Catalysis, Calgary, 1988 (M.J. Phillips and M. Ternan, Eds.), Vol. 3, p. 1238. The Chemical Institute of Canada, Ottawa, 1988) using the catalytic conversion of neopentane as a virtually noncoking probe, the authors found that after reduction at moderate temperatures (573-773 K), Pd/Al{sub 2}O{sub 3} is roughly two orders of magnitude more active than Pd/SiO{sub 2}. An even higher, though transient, catalytic activity is now reported after reducing Pd/Al{sub 2}O{sub 3} at 873 K and extensively purging it in He at this temperature. The IR spectra of adsorbed CO reveal the presence of Pd{sup n+} ions in superactive Pd/Al{sub 2}O{sub 3}; their concentration positively correlates with catalytic activity. Since other potential causes such as strong acid sites are excluded, it is proposed that Pd{sup n+} ions are sites of high catalytic activity. A possible mechanism of their formation and a model of neopentane hydrogenolysis are briefly discussed. Completely reduced Pd appears necessary for neopentane isomerization.

• OSTI ID: 6783224
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 120:1; 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
ADSORPTION
ALKANES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
CORRELATIONS
DEHYDROGENATION
ELEMENTS
HYDROCARBONS
INFRARED SPECTRA
METALS
MINERALS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PALLADIUM
PLATINUM METALS
QUANTITY RATIO
REDUCTION
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SORPTIVE PROPERTIES
SPECTRA
SURFACE PROPERTIES
TRANSITION ELEMENTS