Properties and catalytic activity of nickel phosphate catalyst

Journal Article · Mon Oct 01 04:00:00 EDT 1979 · J. Colloid Interface Sci.; (United States)

DOI:https://doi.org/10.1016/0021-9797(79)90329-1· OSTI ID:6463135

Malinowski, S; Tyblewski, M

Nickel phosphate catalysts were prepared by precipitation from aqueous solutions of Ni(NO/sub 3/)/sub 2/ and (NH/sub 4/)/sub 3/PO/sub 4/ and calcination at 400/sup 0/-900/sup 0/C for three hours. Paper chromatography showed a maximum content of long-chain polyphosphates in catalysts calcined at 500/sup 0/C; higher calcining temperatures resulted in increasing decomposition of polyphosphates to pyro- and orthophosphates. The maximum activity for propylene isopropanol dehydration to propylene at 250/sup 0/-350/sup 0/C occurred at 500/sup 0/C calcining temperature; the active sites are apparently weak Lewis acid sites formed on nickel ions by conversion of Ni-O-P to P-O-P bonds. The maximum activity for isopropanol dehydrogenation to acetone at 350/sup 0/ or 400/sup 0/C occurred at 700/sup 0/C calcining temperature, which coincided with the maximum content of strong Lewis acid sites as detected by adsorbed IR spectroscopy of adsorbed pyridine; this reaction probably involves both Lewis acid and adjacent basic sites, probably oxygen atoms bound to nickel. No free radical or Broensted acid sites were observed by ESR and IR spectroscopy. The results are relevant to the mechanism of activity of calcium nickel phosphate catalysts for dehydrogenation of butenes to butadiene or pentenes to isoprene.

• Research Organization: Warsaw Tech. Univ.
• OSTI ID: 6463135
• Journal Information: J. Colloid Interface Sci.; (United States), Journal Name: J. Colloid Interface Sci.; (United States) Vol. 71:3; ISSN JCISA
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
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ALKENES
BUTENES
CALCINATION
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL ACTIVATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
DEHYDROGENATION
EXPERIMENTAL DATA
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
INFRARED SPECTRA
INORGANIC ACIDS
KINETICS
LEWIS ACIDS
NICKEL COMPOUNDS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PENTENES
PHOSPHATES
PHOSPHORUS COMPOUNDS
PYROLYSIS
REACTION KINETICS
SPECTRA
THERMOCHEMICAL PROCESSES
THERMODYNAMIC ACTIVITY
TRANSITION ELEMENT COMPOUNDS