Infrared study on the formation of isocyanate in the NO and CO reaction on supported IR catalyst

Journal Article · Thu May 01 04:00:00 EDT 1980 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(80)90074-3· OSTI ID:6326021

Solymosi, F; Rasko, J

An infrared study on the formation of isocyanate in the NO + CO reaction on supported Ir catalyst was conducted to elucidate the mechanism of ammonia formation during catalytic treatment of automobile exhaust gases and to develop a new catalytic route for ammonium isocyanate and isocyanic acid. On reduced iridium supported on alumina, silica, titanium dioxide, or magnesium oxide, the isocyanate species (2260-2240 cm/sup -//sup 1/) formed above 200/sup 0/C, with maximum intensity at 280/sup 0/-300/sup 0/C, from gaseous mixtures of nitric oxide and carbon monoxide, and from preadsorbed nitric oxide and gaseous carbon monoxide, but not from preadsorbed carbon monoxide and gaseous nitric oxide. The isocyanate decomposed on evacuation above 300/sup 0/C with formation of carbon monoxide and dioxide and molecular nitrogen. Oxidized iridium had similar spectra of lower intensities. The location of the isocyanate band depended on the support. The results were consistent with a proposed mechanism which accounted for all products detected, and which indicated the dissociative adsorption of nitric oxide as the rate-determining step and migration of the NCO species formed on iridium to the metal of the support oxide.

• Research Organization: Univ. Szeged
• OSTI ID: 6326021
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 63:1; ISSN JCTLA
• Country of Publication: United States
• Language: English

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AMMONIA
AUTOMOBILES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
COMPLEXES
DATA
EXHAUST GASES
EXPERIMENTAL DATA
FLUIDS
GASEOUS WASTES
GASES
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
INFRARED SPECTRA
IRIDIUM COMPLEXES
ISOCYANATES
KINETICS
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN OXIDES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SPECTRA
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
VEHICLES
WASTES