Role of O(-1) ions in the oxidative dehydrogenation of ethane over molybdenum oxide supported on silica gel

Journal Article · Sun Jun 01 00:00:00 EDT 1980 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(80)90107-4· OSTI ID:6320005

Yang, T J; Lunsford, J H

The role of 0(-1) ions in the oxidative dehydrogenation of ethane over molybdenum oxide supported on silica gel was further studied by comparing the ethane dehydrogenation kinetics with molecular oxygen and with nitrous oxide (N/sub 2/O) as oxidizing agent. At 350/sup 0/-450/sup 0/C and 76-380 mm Hg ethane and N/sub 2/O, the reaction was first order in both reactants, the ethylene selectivity was independent of reactant partial pressures, and the activation energies of formation of ethylene and CO/sub 2/ were 18.4 and 28.7 kcal/mole, respectively. With oxygen, the rates of formation of ethylene and CO/sub 2/ were zero order in O/sub 2/ and first order in ethane, and the activation energies of ethylene and CO/sub 2/ formation were 23.3 and 27.2 kcal/mole, respectively. The rates were higher with nitric oxide, especially at the lower temperatures tested, e.g., the rate of ethylene formation at 375/sup 0/C was seven times higher with N/sub 2/O than with O/sub 2/. A mechanism was derived for the formation of ethylene in which the O/sup -/ ions generated by N/sub 2/O decomposition are responsible for hydrogen abstraction in the dissociative adsorption of ethane, and the active site consists of at least two molybdenum ions bridged by an oxygen atom. The presence of ethyl radicals on the catalyst surface was confirmed experimentally.

• Research Organization: Texas A and M Univ.
• OSTI ID: 6320005
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 63:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ACTIVATION ENERGY
ADSORBENTS
ALKANES
ALKENES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
DATA
DEHYDROGENATION
ELEMENTS
ENERGY
ETHANE
ETHYLENE
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
KINETICS
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
NITROGEN COMPOUNDS
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
SILICA GEL
TRANSITION ELEMENT COMPOUNDS
YIELDS