Promoting effects of Se on Rh/SiO sub 2 catalysis for ethene hydroformylation
- Univ. of Tokyo (Japan)
The authors have recently reported the promoting effect of Se on Rh/ZrO{sub 2} catalysis for ethene hydroformylation. The addition of Se electronically modified Rh metal sites around the Se atom to be relatively positive, judging from XPS data which revealed that the oxidation state of Se on Rh particles is {minus}2. This mechanism for the creation of positive metal sites is different from the mechanism induced by site segregation of cationic additives. From IR, isotope effects and TPD studies, Se was suggested to interact with CO and propanoyl intermediate. This interaction should not only be electronic but also geometric by the appropriate distance between Se and adsorbates on Rh sites. For hydroformylation or CO/H{sub 2} reaction on Rh, it has been reported that the activity and selectivity depend on the kind of supports. Support effects can be classified as follows: (1) change of metal particle size, (2) modification of the electronic structure of surface metal site, (3) SMSI effect, and (4) surface groups (for example, OH groups) which directly react or interact with reaction intermediates. Rh on SiO{sub 2} may have a different electronic structure near its Fermi level, and Se would have a different interaction with the Rh to play a different role as promoter as compared to the Rh/ZrO{sub 2} system. In the present paper they report the promoting effects of Se on Rh/SiO{sub 2} catalysis for ethene hydroformylation and the interaction of Se and Rh atoms by kinetics, FT-IR, XPS, and EXAFS in comparison with the case of Se/Rh/ZrO{sub 2}.
- OSTI ID:
- 6984492
- Journal Information:
- Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 132:2; ISSN 0021-9517; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020400* -- Petroleum-- Processing
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ALKENES
ALKYLATION
CATALYSIS
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
ELEMENTS
ETHYLENE
FOURIER TRANSFORMATION
HYDROCARBONS
INFRARED RADIATION
INTEGRAL TRANSFORMATIONS
METALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PLATINUM METALS
PROMOTERS
RADIATIONS
RHODIUM
SELENIUM
SEMIMETALS
SPECTROSCOPY
SYNTHESIS
TRANSFORMATIONS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VALENCE
X-RAY SPECTROSCOPY
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES