An in-situ infrared study of the formation of n- and iso-butyraldehyde from propylene hydroformylation on Rh/SiO[sub 2] and sulfided Rh/SiO[sub 2]

Journal Article · Mon Nov 01 04:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1319· OSTI ID:5088274

Srinivas, G; Chuang, S S ^[1]

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

In situ infrared (IR) technique has been employed to study the reaction of adsorbed CO on Rh/SiO[sub 2] and S-Rh/SiO[sub 2] with C[sub 3]H[sub 6] and H[sub 2], and to investigate the effect of sulfur on the n- and iso-butyraldehyde selectivities during steady-state propylene hydroformylation. CO adsorption on Rh/SiO[sub 2] results in the formation of linear CO and bridged CO adsorbed on Rh[sup 0] sites, and the gemdicarbonyl on Rh[sup +] sites. CO adsorption on S-Rh/SiO[sub 2] results in a high wavenumber Rh[sup +](CO) species in addition to linear CO adsorbed on Rh[sup 0] and the gem-dicarbonyl adsorbed on Rh[sup +]. Sulfur decreases the rate of CO adsorption and inhibits the formation of bridged CO on Rh/SiO[sub 2]. Pulse CO chemisorption on Rh/SiO[sub 2] and S-Rh/SiO[sub 2] reveals that equilibrium constant for CO adsorption on S-Rh/SiO[sub 2] is smaller than that on Rh/SiO[sub 2] at 303 K. The analogy between homogeneous and heterogeneous hydroformylation suggests that enhancement of the isobutryaldehyde formation by adsorbed sulfur could be due to the spacious environment of the protruding Rh[sup +] ion sites ion the S-Rh/SiO[sub 2] allowing isomerization of n-propyl groups before CO insertion. 56 refs., 11 figs., 3 tabs.

• OSTI ID: 5088274
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 144:1; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

10 SYNTHETIC FUELS
100200 -- Synthetic Fuels-- Production-- (1990-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ALKENES
CARBONYLATION
CATALYSIS
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COMPLEXES
HETEROGENEOUS CATALYSIS
HYDROCARBONS
MINERALS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PROPYLENE
RHODIUM COMPLEXES
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SORPTIVE PROPERTIES
SPECTROSCOPY
SURFACE PROPERTIES
TRANSITION ELEMENT COMPLEXES