Kinetic study on the catalytic performance of Rh/TiO/sub 2/ reduced at different temperatures in the CO-H/sub 2/ reaction

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · J. Catal.; (United States)

OSTI ID:5539487

Fujitsu, H; Ikeyama, N; Mochida, I

Catalytic CO-H/sub 2/ reaction on Rh/TiO/sub 2/ reduced at 200, 400, and 500/sup 0/C (Cat-200, -400, -500) for 2 h was kinetically studied at 250/sup 0/C using a circulating reactor and Fourier transform-infrared (FT-IR) spectroscopy to determine how Cat-400 exhibited the highest activity. The rate equation distinguished the best catalyst with zero and first orders in CO and H/sub 2/, respectively, from other catalysts with negative order in CO. The adsorption ability of the catalyst at 200/sup 0/C was comparable to that of Cat-200, and two to three times larger than that of Cat-500, although the ability of Cat-200 was much larger at room temperature. Carbon monoxide adsorbed on the catalysts reversibly as well as irreversibly. IR spectroscopy revealed that the major form of irreversibly adsorbed CO was linear on Cat-200, whereas similar amounts of linear and bridge forms were observed on Cat-400 and Cat-500. These latter forms were highly reactive against hydrogen molecules when no carbon monoxide was present in the gas phase. Based on these results, the highest activity of Cat-400 is ascribed to rhodium metal modified by properly reduced TiO/sub 2/ to show the appropriate adsorption ability of carbon monoxide which least retards the activation of hydrogen according to first-order kinetics. Typical strong metal-support interaction decreases the catalytic activity by decreasing the active sites and strengthening the CO adsorption too much.

• Research Organization: Kyushu Univ., Kasuga, Japan
• OSTI ID: 5539487
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 100:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010408* -- Coal
Lignite
& Peat-- C1 Processes-- (1987-)
ADSORPTION
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
ELEMENTS
FISCHER-TROPSCH SYNTHESIS
FOURIER TRANSFORMATION
INFRARED SPECTRA
INTEGRAL TRANSFORMATIONS
KINETICS
METALS
METHANATION
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
REACTION KINETICS
REDUCTION
RHODIUM
SORPTION
SORPTIVE PROPERTIES
SPECTRA
SURFACE PROPERTIES
SYNTHESIS
TEMPERATURE DEPENDENCE
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSFORMATIONS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS