Effect of water vapor on the selective reduction of NO by methane over cobalt-exchanged ZSM-5

Journal Article · Sun Aug 01 04:00:00 EDT 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1231· OSTI ID:5602232

Li, Y; Battavio, P J; Armor, J N ^[1]

---

1. 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), Journal Name: Journal of Catalysis; (United States) Vol. 142:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010402 -- Coal
Lignite
& Peat-- Purification & Upgrading
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COBALT COMPLEXES
COMPLEXES
FLUIDS
GASES
HETEROGENEOUS CATALYSIS
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE
ION EXCHANGE MATERIALS
KINETICS
MATERIALS
METHANE
MINERALS
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
REDUCTION
SILICATE MINERALS
SORPTIVE PROPERTIES
SURFACE PROPERTIES
TRANSITION ELEMENT COMPLEXES
VAPORS
WATER VAPOR
ZEOLITES