title: Pulsed-field gradient nuclear magnetic resonance study of transport properties of fluid catalytic cracking catalysts.
abstract: Pulsed-field gradient nuclear magnetic resonance (PFG NMR) has been applied to study molecular diffusion in industrial fluid catalytic cracking (FCC) catalysts and in USY zeolite for a broad range of molecular displacements and temperatures. The results of this study have been used to elucidate the relevance of molecular transport on various displacements for the rate of molecular exchange between catalyst particles and their surroundings. It turned out that this rate, which may determine the overall rate and selectivity of FCC process, is primarily related to the diffusion mode associated with displacements larger than the size of zeolite crystals located in the particles but smaller than the size of the particles. This conclusion has been confirmed by comparative studies of the catalytic performance of different FCC catalysts.
authors.affiliation: Fakultät für Physik und Geowissenschaften, Universität Leipzig, D-04103 Leipzig, Germany. kortunov@physik.uni-leipzig.de
authors.forename: P
authors.initials: P
authors.lastname: Kortunov
authors.forename: S
authors.initials: S
authors.lastname: Vasenkov
authors.forename: J
authors.initials: J
authors.lastname: Kärger
authors.forename: M
authors.initials: M
authors.lastname: Fé Elía
authors.forename: M
authors.initials: M
authors.lastname: Perez
authors.forename: M
authors.initials: M
authors.lastname: Stöcker
authors.forename: G K
authors.initials: GK
authors.lastname: Papadopoulos
authors.forename: D
authors.initials: D
authors.lastname: Theodorou
authors.forename: B
authors.initials: B
authors.lastname: Drescher
authors.forename: G
authors.initials: G
authors.lastname: McElhiney
authors.forename: B
authors.initials: B
authors.lastname: Bernauer
authors.forename: V
authors.initials: V
authors.lastname: Krystl
authors.forename: M
authors.initials: M
authors.lastname: Kocirik
authors.forename: A
authors.initials: A
authors.lastname: Zikanova
authors.forename: H
authors.initials: H
authors.lastname: Jirglova
authors.forename: C
authors.initials: C
authors.lastname: Berger
authors.forename: R
authors.initials: R
authors.lastname: Gläser
authors.forename: J
authors.initials: J
authors.lastname: Weitkamp
authors.forename: E W
authors.initials: EW
authors.lastname: Hansen
mesh_terms: D002384:Catalysis; D004058:Diffusion; D009682:Magnetic Resonance Spectroscopy; D010316:Particle Size; D016062:Porosity; D017641:Zeolites / Q000737:chemistry*
chemical_list: D017641:Zeolites