The surface chemistry of isolated and aggregated silica-bound rhodium complexes

Journal Article · Thu Nov 30 23:00:00 EST 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90272-8· OSTI ID:7055418

Cannon, K C; White, J M ^[1]

---

1. Univ. of Texas, Austin (USA)

The chemisorption activity of silica-bound molecular Rh complexes has been studied using Fourier transform infrared, temperature-programmed desorption, and X-ray photoelectron spectroscopy on samples treated variously with CO, NO, and H{sub 2}. Beginning with a {mu}-oxo rhodium carbonyl species, treatment with NO leads to no (bis)nitrosyl rhodium complexes but to a mixture of an oxygen adduct and a nitrite/nitrate complex. Treatment of the latter with CO does not form isocyanate; treatment of it with H{sub 2} leads to an aggregated Rh complex and an unidentified complex, probably involving nitrogen and derived from the nitrate/nitrite complex. Treatment of the aggregated complex with NO and CO leads to some isocyanate on the Rh but none on the support. High-temperature treatment under vacuum leads to irreversible sintering after which the Rh behaves like conventional Rh metal particles with respect to formation of isocyanate on both the metal and the support upon exposure to NO and CO. The authors conclude that isocyanate formation depends strongly on the form of the Rh.

• OSTI ID: 7055418
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 120:2; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CATALYST SUPPORTS
CHALCOGENIDES
CHEMICAL PROPERTIES
CHEMICAL REACTIONS
CHEMISORPTION
COMPLEXES
CONTROL
DESORPTION
ELECTRON SPECTROSCOPY
ELEMENTS
FABRICATION
FOURIER TRANSFORMATION
HYDROGEN
HYDROGEN COMPOUNDS
INFRARED SPECTRA
INORGANIC ACIDS
INTEGRAL TRANSFORMATIONS
ISOCYANATES
MINERALS
NITRATES
NITRIC ACID
NITRITES
NITROGEN COMPOUNDS
NONMETALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
RHODIUM COMPLEXES
SEPARATION PROCESSES
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SINTERING
SORPTION
SPECTRA
SPECTROSCOPY
SURFACE PROPERTIES
TEMPERATURE CONTROL
TRANSFORMATIONS
TRANSITION ELEMENT COMPLEXES
X-RAY SPECTROSCOPY