Methane oxidation over dual redox catalysts
Catalytic oxidation of methane to partial oxidation products, primarily formaldehyde and C[sub 2] hydrocarbons, was found to be directed by the catalyst used. In this project, it was discovered that a moderate oxidative coupling catalyst for C[sub 2] hydrocarbons, zinc oxide, is modified by addition of small amounts of Cu and Fe dopants to yield fair yields of formaldehyde. A similar effect was observed with Cu/Sn/ZnO catalysts, and the presence of a redox Lewis acid, Fe[sup III] or Sn[sup IV], was found to be essential for the selectivity switch from C[sub 2] coupling products to formaldehyde. The principle of double doping with an oxygen activator (Cu) and the redox Lewis acid (Fe, Sn) was pursued further by synthesizing and testing the CuFe-ZSM-5 zeolite catalyst. The Cu[sup II](ion exchanged) Fe[sup III](framework)-ZSM-5 also displayed activity for formaldehyde synthesis, with space time yields exceeding 100 g/h-kg catalyst. However, the selectivity was low and earlier claims in the literature of selective oxidation of methane to methanol over CuFe-ZSM-5 were not reproduced. A new active and selective catalytic system (M=Sb,Bi,Sn)/SrO/La[sub 2]O[sub 3] has been discovered for potentially commercially attractive process for the conversion of methane to C[sub 2] hydrocarbons, (ii) a new principle has been demonstrated for selectivity switching from C[sub 2] hydrocarbon products to formaldehyde in methane oxidations over Cu,Fe-doped zinc oxide and ZSM-5, and (iii) a new approach has been initiated for using ultrafine metal dispersions for low temperature activation of methane for selective conversions. Item (iii) continues being supported by AMOCO while further developments related to items (i) and (ii) are the objective of our continued effort under the METC-AMOCO proposed joint program.
- Research Organization:
- Lehigh Univ., Bethlehem, PA (United States). Zettlemoyer Center for Surface Studies
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG21-89MC26039
- OSTI ID:
- 6857200
- Report Number(s):
- DOE/MC/26039-3111; ON: DE92012454
- Country of Publication:
- United States
- Language:
- English
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Methane oxidation over dual redox catalysts
Methane oxidation over dual redox catalysts. Quarterly technical progress report, July--September 1989
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
METHANE
OXIDATION
CATALYSTS
ZINC OXIDES
CATALYTIC EFFECTS
COPPER
DOPED MATERIALS
FORMALDEHYDE
HYDROCARBONS
IRON
PARTIAL OXIDATION PROCESSES
PROGRESS REPORT
SPECIFICITY
TEMPERATURE EFFECTS
ZEOLITES
ALDEHYDES
ALKANES
CHALCOGENIDES
CHEMICAL REACTIONS
DOCUMENT TYPES
ELEMENTS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
METALS
MINERALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SILICATE MINERALS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS
ZINC COMPOUNDS
400201* - Chemical & Physicochemical Properties
010408 - Coal
Lignite
& Peat- C1 Processes- (1987-)