Effect of water vapor on the selective reduction of NO by methane over cobalt-exchanged ZSM-5
- Air Products and Chemicals, Inc., Allentown, PA (United States)
The effect of water vapor on the reduction of NO with CH[sub 4] in excess O[sub 2] over a Co-ZSM-5 catalyst was studied. The presence of 2% water significantly decreases the NO conversion at T [le] 450[degrees]C but has less of an effect at T [ge] 500[degrees]C. The selectivity of methane toward NO reduction was enhanced by the presence of water at low temperatures and is unchanged at high temperatures. This inhibition is reversible upon eliminating water from the system. The effect of water is dependent on the level of water added, space velocity, reaction temperature, and level of methane in the feed. The addition of water increases the empirical reaction order with respect to either CH[sub 4] or NO from a fractional order to first order. Temperature-programmed desorption studies show that the amount of NO adsorption on Co-ZSM-5 is significantly reduced if it is not fully dried, and the competitive adsorption between H[sub 2]O and NO is probably the cause of the inhibition by water. In addition, Co-ZSM-5 is capable of removing NO and CO simultaneously in either a dry or wet feed. 25 refs., 12 figs., 2 tabs.
- OSTI ID:
- 5602232
- Journal Information:
- Journal of Catalysis; (United States), Vol. 142:2; ISSN 0021-9517
- Country of Publication:
- United States
- Language:
- English
Similar Records
Selective reduction of NO{sub x} by methane on Co-ferrierites
Highly Selective H2 Separation Zeolite Membranes for Coal Gasification Membrane Reactor Applications
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
COBALT COMPLEXES
CATALYTIC EFFECTS
NITRIC OXIDE
REDUCTION
ZEOLITES
CARBON MONOXIDE
CATALYSTS
CHEMICAL REACTION KINETICS
HETEROGENEOUS CATALYSIS
ION EXCHANGE
METHANE
SORPTIVE PROPERTIES
WATER VAPOR
ALKANES
CARBON COMPOUNDS
CARBON OXIDES
CATALYSIS
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
FLUIDS
GASES
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
KINETICS
MATERIALS
MINERALS
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SILICATE MINERALS
SURFACE PROPERTIES
TRANSITION ELEMENT COMPLEXES
VAPORS
400201* - Chemical & Physicochemical Properties
010402 - Coal
Lignite
& Peat- Purification & Upgrading