Transient infrared study of methanation and ethylene hydroformylation over Rh/SiO[sub 2] catalysts

Journal Article · Sun Feb 28 23:00:00 EST 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1083· OSTI ID:6305002

Balakos, M W; Chuang, S S.C.; Srinivas, G ^[1]

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

Determination of reactivity and surface coverage of intermediates has been a challenging goal in fundamental research of heterogeneous catalysis. First Happel et al. and later Biloen and co-workers employed the use of a transient rate tracer method for the determination of the intrinsic rate constant, k, and the fractional surface coverage, [Theta], of intermediates for steady-state carbon monoxide hydrogenation. The method was further developed and termed steady-state isotopic transient kinetic analysis (SSITKA) by Goodwin and co-workers. SSITKA is a transient method for the investigation of kinetics and mechanism of heterogeneous catalysis under steady-state conditions. The approach involves an abrupt switch from an inlet reactant species to a corresponding isotopically labeled species. The advantage of SSITKA from other transient methods is that the chemical environment of the catalyst surface does not vary with the transient state of the isotopic tracer, yielding tracer response curves for the determination of k and [Theta]. The method has been applied in the investigation of the mechanism of methanation, Fischer-Tropsch synthesis, ammonia synthesis, and partial oxidation of methane. In situ infrared absorption spectroscopy (IR) allows for the direct observation of absorbed species under reaction conditions. Incorporation of in situ IR spectroscopy with SSITKA may provide information on the surface coverages of IR observable species under reaction conditions and has the potential for distinguishing between reaction intermediates and surface absorbed spectator species. This paper reports the use of IR combined with SSITKA to study methanation and ethylene hydroformylation on Rh/SiO[sub 2] at 513 K and 0.1 MPa. 20 refs., 3 figs.

• OSTI ID: 6305002
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 140:1; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

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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
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ETHYLENE
HETEROGENEOUS CATALYSIS
HYDROCARBONS
KINETICS
METHANATION
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION INTERMEDIATES
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
RHODIUM COMPOUNDS
SILICON COMPOUNDS
SILICON OXIDES
SPECTROSCOPY
STEADY-STATE CONDITIONS
TRANSITION ELEMENT COMPOUNDS