Characterization of Mg and Mn substitution in AlPO[sub 4]-5

Journal Article · Sun Nov 01 00:00:00 EST 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90030-L· OSTI ID:5601940

Parrillo, D J; Pereira, C; Kokotailo, G T; Gorte, R J ^[1]

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1. Univ. of Pennsylvania, Philadelphia, PA (United States)

The authors have examined the framework substitution of Mg and Mn into the AlPO[sub 4]-5 structure by studying the adsorption of reactive probe molecules, including ethylamine, isopropylamine, 2-propanol, and propene. Lattice parameters from X-ray diffraction suggests that there is a maximum framework substitution of 5 mol% for both metals. However, samples with 5 mol% Mg or Mn appear to contain large concentrations of defects in the structure, based on the observation of slow adsorption of branched alkanes. In simultaneous temperature-programmed-desorption (TPD)/thermogravimetric-analysis (TGA) measurements, both amines reacted to an olefin and ammonia in a well-defined decomposition feature between 575 and 650 K for isopropylamine and between 625 and 675 K for ethylamine. By comparison with similar results on high-silica zeolites, the sites which decompose the amines are known to be Bronsted acid sites and decomposition occurs through an alkylammonium ion intermediate. For low concentrations of Mn and Mg (<1 mol%), the moles of isopropylamine and ethylamine which decompose in TPD-TGA are the same and equal to the moles of substituted metal atoms, indicating that the metals substitute for the Al in the framework to form Bronsted-acid sites. These same sites also catalyze the dehydration of 2-propanol above 400 K and the oligomerization of propene at 300 K. 23 refs., 6 figs., 2 tabs.

• OSTI ID: 5601940
• Journal Information: Journal of Catalysis; (United States), Vol. 138:1; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
10 SYNTHETIC FUELS
ALUMINIUM PHOSPHATES
SORPTIVE PROPERTIES
AMINES
ADSORPTION
MAGNESIUM COMPLEXES
MANGANESE COMPLEXES
PROPANOLS
DEHYDRATION
PROPYLENE
POLYMERIZATION
ALKANES
BROENSTED ACIDS
CATALYTIC EFFECTS
CRYSTAL DEFECTS
HETEROGENEOUS CATALYSIS
LATTICE PARAMETERS
REACTION INTERMEDIATES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
X-RAY DIFFRACTION
ALCOHOLS
ALKALINE EARTH METAL COMPLEXES
ALKENES
ALUMINIUM COMPOUNDS
CATALYSIS
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPLEXES
CRYSTAL STRUCTURE
DIFFRACTION
GRAVIMETRIC ANALYSIS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INORGANIC ACIDS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
SCATTERING
SORPTION
SURFACE PROPERTIES
TEMPERATURE RANGE
TRANSITION ELEMENT COMPLEXES
400201* - Chemical &amp; Physicochemical Properties
100200 - Synthetic Fuels- Production- (1990-)