Infrared study of the behavior of CO, NO, and CO + NO over Rh/Al/sub 2/O/sub 3/ catalysts
Infrared spectroscopy was used to study the interaction of carbon monoxide and nitric oxide on a 0.475% Rh/Al/sub 2/O/sub 3/ catalyst. Both CO and NO readily adsorb on a prereduced catalyst surface. NO is not observed spectroscopically on preoxidized catalysts, yet isocyanate is produced during subsequent displacement by CO. The adsorption of CO on a preoxidized catalyst parallels the reduction of the catalyst. At temperatures in excess of 250/sup 0/C and mixed feeds with CO/NO greater than or equal to 1, a large buildup of isocyanate is observed on the support. At temperatures greater than 300/sup 0/C an infrared band attributed to adsorbed cyanide ion is observed near 2150 cm/sup -1/. Experiments involving displacement of NO by CO, displacement of CO by NO, and coadsorption of CO + NO show that contiguous rhodium surfaces are necessary for isocyanate production. Though the rhodium gem-dicarbonyl species, Rh(CO)/sub 2/, was observed, there was no experimental evidence demonstrating the presence of Rh(NO)/sub 2/ or Rh(NO)(CO) complexes.
- Research Organization:
- General Motors Research Labs., Warren, MI
- OSTI ID:
- 5312800
- Journal Information:
- J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 109:1; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
330701* -- Emission Control-- Nitrogen Oxides
330702 -- Emission Control-- Carbon Monoxide
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ADSORPTION
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC CONVERTERS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
CYANIDES
ELEMENTS
EQUIPMENT
INFRARED SPECTRA
ISOCYANATES
METALS
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
POLLUTION CONTROL EQUIPMENT
REACTION INTERMEDIATES
RHODIUM
RHODIUM COMPLEXES
SORPTION
SPECTRA
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENTS