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 · Mon Feb 01 00:00:00 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]

---

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), Vol. 139:2; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
10 SYNTHETIC FUELS
CARBON MONOXIDE
CHEMISORPTION
ETHYLENE
CARBONYLATION
NITRATES
CATALYTIC EFFECTS
SORPTIVE PROPERTIES
RHODIUM CHLORIDES
RHODIUM COMPOUNDS
ABSORPTION SPECTROSCOPY
CATALYST SUPPORTS
CATALYSTS
DECOMPOSITION
HETEROGENEOUS CATALYSIS
HYDROGEN
PYROLYSIS
REDUCTION
SILICON OXIDES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K
ALKENES
CARBON COMPOUNDS
CARBON OXIDES
CATALYSIS
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
NITROGEN COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
SEPARATION PROCESSES
SILICON COMPOUNDS
SORPTION
SPECTROSCOPY
SURFACE PROPERTIES
TEMPERATURE RANGE
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
400201* - Chemical & Physicochemical Properties
100200 - Synthetic Fuels- Production- (1990-)