Mechanisms and controlling characteristics of the catalytic oxidation of methane

Technical Report · Wed Jan 01 04:00:00 EST 1992

DOI:https://doi.org/10.2172/7152084· OSTI ID:7152084

Klier, K; Simmons, G W; Herman, R G; Miller, A C

We have demonstrated in this work (1) that methane is readily activated at mild conditions (100[degree]C, 1 torr) over a relatively noble metal, Pd. This was observed using a stepped and kinked Pd(679) crystal (1), and other crystal faces are now being investigated to establish whether the cracking of the C-H bond of methane on Pd is structure sensitive or structure insensitive. Oxygen chemisorption is extremely structure sensitive: weakly bonded, highly reactive oxygen overlayers form on Pd(100) surface (2), while strongly bonded, moderately reactive oxygen overlayers form on Pd(111) and Pd(679). Reaction of the weakly bonded oxygen with surface carbide gives rise to CO[sub 2] over clean Pd(100) but to CO over halogen-doped Pd(100) (3--5). The effect of halogens is primarily ensemble-controlling, or oxygen-supply restricting, but long range influence of surface Cl on the strength of the Pd-O bond has also been observed (3). Because the overall chemistry of methane activation with the subsequent oxidation gives rise to the very important oxidative reforming CH[sub 4] + 1/2 O[sub 2] [yields][sub Pd/Cl] CO + 2 H[sub 2], Pd/Cl we plan to continue our study of this reaction in detail over Pd(100) (completed), Pd(111) (initiated), Pd(311) (initiated), Pd(110) (to be initiated), and Pd(679) (completed), without and with the halogen modifiers.

• Research Organization: Lehigh Univ., Bethlehem, PA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-86ER13580
• OSTI ID: 7152084
• Report Number(s): DOE/ER/13580-T2; ON: DE93005719
• Country of Publication: United States
• Language: English

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AIR
ALCOHOLS
ALDEHYDES
ALKANES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL ACTIVATION
CHEMICAL BONDS
CHEMICAL REACTIONS
CLEAVAGE
CRYSTAL STRUCTURE
DOCUMENT TYPES
DOPED MATERIALS
ELEMENTS
FLUIDS
FORMALDEHYDE
GASES
HYDROCARBONS
HYDROGEN
HYDROXY COMPOUNDS
MATERIALS
METALS
METHANE
METHANOL
MICROSTRUCTURE
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PALLADIUM
PARTIAL OXIDATION PROCESSES
PLATINUM METALS
PROGRESS REPORT
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS