Infrared studies of the interactions of C[sub 2]H[sub 4] and H[sub 2] with Rh[sup +](CO)[sub 2] and CO adsorbed on RhCl[sub 3]/SiO[sub 2] and Rh(NO[sub 3])[sub 3]/SiO[sub 2]

Journal Article · Sun Jan 31 23:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1043· OSTI ID:6259455

Chuang, S S.C.; Srinivas, G; Mukherjee, A ^[1]

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1. Univ. of Akron, OH (United States)

Interactions of C[sub 2]H[sub 4]/H[sub 2] with Rh[sup +](CO)[sub 2]/SiO[sub 2] and CO adsorbed on RhCl[sub 3]/SiO[sub 2] and Rh(NO[sub 3])[sub 3]/SiO[sub 2] and the activity of these catalysts for ethylene hydroformylation have been studied by infrared spectroscopy. Chemisorption of CO on RhCl[sub 3]/SiO[sub 2] and Rh(NO[sub 3])[sub 3]/SiO[sub 2] at 298 K results in the formation of linear CO on Rh[sup +] (or Rh[sup +2]) and Rh[sup +3] sites as well as gem-dicarbonyl. Temperature-programmed decomposition studies show that thermal stability of these adsorbed CO species decreases in the following order: linear CO on Rh[sup +] of RhCl[sub 3]/SiO[sub 2] > Rh[sup +](CO)[sub 2] on Rh(NO[sub 3])[sub 3]/SiO[sub 2] > Rh[sup +](CO)[sub 2] and linear CO on Rh[sup +3] on RhCl[sub 3]/SiO[sub 2]. Linear CO on Rh[sup +] sites is more active than Rh[sup +](CO)[sub 2] on either Rh(NO[sub 3])[sub 3]/SiO[sub 2] or RhCl[sub 3]/SiO[sub 2] at 298 K toward C[sub 2]H[sub 4] and H[sub 2] leading to the formation of propionaldehyde. Gem-dicarbonyl is observed as a dominant CO species adsorbed on RhCl[sub 3]/SiO[sub 2] while both gem-dicarbonyl and linear CO on Rh[sup 0] sites are found on Rh(NO[sub 3])[sub 3]/SiO[sub 2] during ethylene hydroformylation at 393 K and 1 MPa. RhCl[sub 3]/SiO[sub 2] shows higher hydroformylation selectivity than Rh(NO[sub 3])[sub 3]/SiO[sub 2]. RhCl[sub 3]/SiO[sub 2] is less susceptible to reduction by the reactant mixture than Rh(NO[sub 3])[sub 3]/SiO[sub 2], resulting in higher hydroformylation selectivity. Increasing the reaction temperature from 393 to 513 K results in the reduction of RhCl[sub 3] and Rh(NO[sub 3])[sub 3] to reduced Rh crystallites. Both catalysts remain active for hydroformylation and exhibit similar hydroformylation selectivities at 513 K. 60 refs., 8 figs., 2 tabs.

• DOE Contract Number: FG22-87PC79923
• OSTI ID: 6259455
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 139:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

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10 SYNTHETIC FUELS
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ALKENES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLATION
CATALYSIS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
CHLORIDES
CHLORINE COMPOUNDS
DECOMPOSITION
ELEMENTS
ETHYLENE
HALIDES
HALOGEN COMPOUNDS
HETEROGENEOUS CATALYSIS
HYDROCARBONS
HYDROGEN
NITRATES
NITROGEN COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS
REDUCTION
REFRACTORY METAL COMPOUNDS
RHODIUM CHLORIDES
RHODIUM COMPOUNDS
SEPARATION PROCESSES
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS