Acid and catalytic properties of nonstoichiometric aluminum borates

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

DOI:https://doi.org/10.1016/0021-9517(89)90048-1· OSTI ID:6835317

Peil, K P; Marcelin, G ^[1]; Galya, L G ^[2]

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1. Univ. of Pittsburgh, PA (USA)
2. Univ. of Pittsburgh Applied Research Center, PA (USA)

This paper details an investigation on the structure-acidity-catalytic activity relationship in aluminum borate mixed oxides. This aluminum borate mixed oxide is amorphous, is refractory, and exhibits properties which are dependent on the exact stoichiometry of the material. A series of catalysts with B/Al ratios ranging from 0 to 1 was prepared and characterized with respect to surface area, pore volume, and thermal stability. Nuclear magnetic resonance spectroscopy of {sup 11}B and {sup 27}Al was used to determine the local structure. Two boron species were identified: a tetrahedral BO{sub 4} and a trigonal BO{sub 3}. The relative amounts of the two boron species were dependent on the B/Al stoichiometry. Three aluminum species were identified: a tetrahedral AlO{sub 4}, an octahedral AlO{sub 6}, and an AlO{sub 4} with four B next-nearest neighbors. The strength and concentration of acid sites present on the surface of the aluminum borates were determined using adsorbed indicators. The presence and coordination of boron were seen to have a dramatic effect on the acidity of these materials with the acidity being closely related to the relative concentration of BO{sub 4}. 2-Propanol dehydration was used as a probe reaction to measure the acidity. Results from this reaction have shown these materials to indeed by highly acidic and catalytically active.

• OSTI ID: 6835317
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 115:2; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALCOHOLS
ALUMINIUM 27
ALUMINIUM COMPOUNDS
ALUMINIUM ISOTOPES
ALUMINIUM OXIDES
BORATES
BORON 11
BORON COMPOUNDS
BORON ISOTOPES
BORON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CRYSTAL STRUCTURE
DEHYDRATION
DISPERSIONS
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MICROSTRUCTURE
MIXTURES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
POROSITY
PROPANOLS
QUANTITY RATIO
RESONANCE
STABILITY
STABLE ISOTOPES
STOICHIOMETRY
SURFACE AREA
SURFACE PROPERTIES