Acidity of H-Y zeolites: Role of extralattice aluminum

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

DOI:https://doi.org/10.1006/jcat.1993.1041· OSTI ID:6259587

Shertukde, P V; Hall, W K; Dereppe, J M; Marcelin, G ^[1]

---

1. Univ. of Pittsburgh, PA (United States)

The nature of extralattice aluminum and its effect on acidity in zeolites was studied. A series of zeolites (some commercial), dealuminated by various methods, were obtained having Si/Al ratios between 1.5 and 20. These were characterized using volumetric sorption, XRD, AA, NMR, and reaction studies. Samples dealuminated using ammonium hexafluorosilicate were found to contain little or no extralattice aluminum. In contrast, steam-dealuminated zeolites had large amounts of extralattice aluminum. In some cases a significant portion of the extralattice aluminum was unobservable by [sup 27]Al NMR, suggesting the existence of an aluminum species of low symmetry. Proton NMR indicated that all the protons were associated with the lattice aluminum atoms. Depending on the preparation history, different groups of H-Y zeolites exhibited different maxima in catalytic activity as a function of aluminum content. The maxima in catalytic activity for n-pentane cracking was found to be a function of both lattice and extralattice aluminum contents. 29 refs., 6 figs., 3 tabs.

• DOE Contract Number: FG02-87ER13774
• OSTI ID: 6259587
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 139:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400 -- Petroleum-- Processing
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ALKANES
ALUMINIUM
BARYONS
BROENSTED ACIDS
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTIONS
COHERENT SCATTERING
CRACKING
DECOMPOSITION
DIFFRACTION
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
HADRONS
HETEROGENEOUS CATALYSIS
HYDROCARBONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MAGNETIC RESONANCE
MATERIALS
METALS
MINERALS
NUCLEAR MAGNETIC RESONANCE
NUCLEONS
ORGANIC COMPOUNDS
PENTANE
PROTONS
PYROLYSIS
RESONANCE
SCATTERING
SILICATE MINERALS
SORPTION
SPECTROSCOPY
SYMMETRY
THERMOCHEMICAL PROCESSES
X-RAY DIFFRACTION
ZEOLITES