Activation of methane by transition metal-substituted aluminophosphate molecular sieves
Recent experiments in our laboratory have demonstrated that aluminophosphate molecular sieves substituted with cobalt and cobalt/silicon combinations and having the AlPO{sub 4}-34 or AlPO{sub 4}-5 structure activate methane starting at {approximately}350{degree}C. Between 400 and 500{degree}C the rate of methane conversion increases steadily with typical conversion efficiencies at 500{degree}C ranging from 15 to 60%. The cobalt and silicon substituted AlPO{sub 4}-34 structure (CoAPSO-34) produces ethylene, ethane, propylene, and propane in varying proportions, depending on reactions conditions. The cobalt-substituted AlPO{sub 4}-5 (CoAPSO-5) produces propylene in very high yield with ethane, ethylene, and propane also seen. Analogous aluminophosphate molecular sieves substituted with magnesium or silicon, but containing no transition metal (e.g., SAPO-34, MAPO-5), do not activate methane under the conditions described above. The activation mechanism is based on reduction of the cobalt(III) form of the molecular sieve to the cobalt(II) form with accompanying oxidative dehydrogenation of the methane. Reoxidation of the cobalt(II) for to the cobalt(III) form can be done either chemically (e.g., using O{sub 2}) or electrochemically. 7 refs., 2 figs., 1 tab.
- Research Organization:
- Argonne National Lab., IL (USA)
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 7249449
- Report Number(s):
- CONF-900402-4; ON: DE90005663
- Resource Relation:
- Conference: 199. national meeting of the American Chemical Society, Boston, MA (USA), 22-27 Apr 1990
- Country of Publication:
- United States
- Language:
- English
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Activation of methane by transition metal-substituted aluminophosphate molecular sieves
Activation of methane by transition metal-substituted aluminophosphate molecular sieves
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALUMINIUM PHOSPHATES
MOLECULAR SIEVES
METHANE
CHEMICAL ACTIVATION
CATALYSIS
CATALYTIC EFFECTS
COBALT
DEHYDROGENATION
HYDROCARBONS
ADSORBENTS
ALKANES
ALUMINIUM COMPOUNDS
CHEMICAL REACTIONS
ELEMENTS
METALS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHATES
PHOSPHORUS COMPOUNDS
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties