Reduction of NO by H/sub 2/-CO mixtures over silica-supported rhodium: infrared and kinetic studies

Journal Article · Wed Aug 01 04:00:00 EDT 1984 · J. Catal.; (United States)

OSTI ID:6387585

Hecker, W C; Bell, A T

The kinetics of NO reduction by H/sub 2/-CO mixtures have been investigated over a Rh/SiO/sub 2/ catalyst. Nearly 90% of the reduction can be ascribed to H/sub 2/. The presence of CO retards the rate of NO reduction, presumably due to competitive adsorption with H/sub 2/. The formation of urea is a direct result of NO reduction by H/sub 2/ and CO. The catalyst activity is 50% higher when the catalyst is preoxidized rather than prereduced. N/sub 2/O, N/sub 2/, NH/sub 3/, and (NH/sub 2/)/sub 2/CO are formed over the prereduced catalyst. NH/sub 3/ formation is largely suppressed when the catalyst is preoxidized and a product believed to be HNCO is formed instead of urea. In situ infrared spectra of the catalyst show that for NO conversions below 70%, the surface is dominated by adsorbed NO. At higher conversions, bands are also observed for adsorbed CO, but none for isocyanate species attached to Rh.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 6387585
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 88:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
ELEMENTS
EXPERIMENTAL DATA
HYDROGEN
INFORMATION
METALS
MINERALS
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
NUMERICAL DATA
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
REDUCTION
RHODIUM
SILICA
SILICON COMPOUNDS
SILICON OXIDES
TRANSITION ELEMENTS