The effect of sodium poisoning on dealuminated Y-type zeolites

Journal Article · Sat Jul 01 00:00:00 EDT 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90303-5· OSTI ID:7261163

Fritz, P O; Lunsford, J H ^[1]

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1. Texas A and M Univ., College Station (USA)

Dealuminated zeolites prepared both hydrothermally and using silicon tetrachloride were investigated to determine the effect of sodium addition on their catalytic activities. These materials were found to have drastically reduced activities upon sodium addition with each sodium atom effectively neutralizing the catalytic activity previously thought to be due to five framework Broensted acid sites. These results are interpreted to mean that isolated framework Al atoms are a necessary but insufficient condition for strong acidity, and only about one-fifth of the framework Al atoms are associated with this strong acidity. Extraframework Al is believed to impart, through inductive effects, strong acidity to these framework Broensted sites. An infrared study of the hydroxyl region revealed bands at 3,675 and 3,595-3,610 cm{sup {minus}1} ({plus minus}2 cm{sup {minus}1}) that are attributed to protons associated with different types of extraframework aluminium oxide or oxyhydroxide. A band at 3,695 cm{sup {minus}1} is attributed to Na{sup +} interacting with water which is hydrogen-bonded to a framework oxygen atom. A narrow band at 3,602 cm{sup {minus}1} is attributed to a highly acidic Broensted site in the zeolite lattice.

• OSTI ID: 7261163
• Journal Information: Journal of Catalysis; (USA), Vol. 118:1; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
SODIUM
CATALYTIC EFFECTS
ZEOLITES
CATALYSIS
ADDITIVES
ALUMINIUM OXIDES
CATALYTIC CRACKING
INFRARED SPECTRA
MICROSTRUCTURE
PETROLEUM FRACTIONS
POISONING
YTTRIUM
ALKALI METALS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
CRACKING
CRYSTAL STRUCTURE
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
METALS
MINERALS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM
PYROLYSIS
SPECTRA
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS
020400* - Petroleum- Processing