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Titolo:
Shape-selective catalysts: quasi-two-dimensional Pd-particles encapsulatedin graphite
Autore:
Mastalir, A; Kiraly, Z; Walter, J; Notheisz, F; Bartok, M;
Indirizzi:
Univ Szeged, Dept Organ Chem, H-6720 Szeged, Hungary Univ Szeged Szeged Hungary H-6720 ept Organ Chem, H-6720 Szeged, Hungary Univ Szeged, Dept Colloid Chem, H-6720 Szeged, Hungary Univ Szeged Szeged Hungary H-6720 t Colloid Chem, H-6720 Szeged, Hungary Osaka Univ, Dept Mat Sci & Proc, Suita, Osaka 5650871, Japan Osaka Univ Suita Osaka Japan 5650871 & Proc, Suita, Osaka 5650871, Japan
Titolo Testata:
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
fascicolo: 1-2, volume: 175, anno: 2001,
pagine: 205 - 213
SICI:
1381-1169(20011023)175:1-2<205:SCQPE>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
QUASI-2-DIMENSIONAL PALLADIUM NANOPARTICLES; INTERCALATION COMPOUNDS; CARBON-COMPOUNDS; HETEROGENEOUS CATALYSIS; SUPPORTED PALLADIUM; LAMELLAR COMPOUNDS; TRANSFORMATION; METALS; HYDROGENATION; CHEMISTRY;
Keywords:
palladium; graphite; encapsulation; H-2 sorption; TEM; 1-butene; cis-2-pentene; shape-selectivity; rearrangement; deactivation;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
34
Recensione:
Indirizzi per estratti:
Indirizzo: Mastalir, A Univ Szeged, Dept Organ Chem, Dom Ter 8, H-6720 Szeged, Hungary Univ Szeged Dom Ter 8 Szeged Hungary H-6720 0 Szeged, Hungary
Citazione:
A. Mastalir et al., "Shape-selective catalysts: quasi-two-dimensional Pd-particles encapsulatedin graphite", J MOL CAT A, 175(1-2), 2001, pp. 205-213

Abstract

Pd-graphites were prepared by reduction of PdCl2-graphite intercalation compounds (PdCl2-GICs). Transmission electron microscope (TEM) measurements on the samples indicated that Pd nanoparticles with a wide size distributionwere formed, mostly encapsulated inside the graphite host. The quasi-two-dimensional character of the Pd nanoparticles was confirmed by H-2 sorption studies, which revealed the absence of P-hydride formation over a broad range of pressure. Although the structures of the three Pd-graphites studied were very similar, differences were found between them in terms of their catalytic performance in the gas-phase reactions of 1-butene, cis-2-pentene and cyclohexene. It was established that the transformations of both 1-buteneand cis-2-pentene took place in the interlamellar space of the graphite, whereas, in consequence of the the non-planar character of the substrate, the diffusion of cyclohexene between the graphite layers was sterically hindered. This molecular sieving effect implies that the Pd-graphites may be regarded as shape-selective catalysts. Pretreatment at 473 K was found to lower the catalytic activities considerably. The experimental evidence indicated that restructuring of the Pd crystallites resulted in a moderate aggregation of the active Pd-particles available for the reactant molecules. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 19/09/20 alle ore 17:36:55