Characterization and Fourier transform infrared studies of the effects of TiO/sub 2/ crystal phases during CO oxidation on Pt/TiO/sub 2/ catalysts

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · J. Catal.; (United States)

OSTI ID:5442142

Lane, G S; Wolf, E E

The catalytic oxidation of CO was investigated on Pt/TiO/sub 2/ catalysts in an infrared cell reactor to study the influence of strong metal-support interaction effects on oxidation reactions and of using different crystal forms of TiO/sub 2/. Catalysts were prepared using rutile and anatase TiO/sub 2/ and were characterized by chemisorption, X-ray diffraction, and X-ray photoelectron spectroscopy. Hydrogen reduction at 500/sup 0/C suppresses CO and H/sub 2/ chemisorption and leads to changes in Pt 4f/sub 7/2/ electron binding energies for both phases of TiO/sub 2/. The anatase catalysts show an infrared absorption band around 2091 cm/sup -1/ which is assigned to linear-bonded CO; whereas, the rutile catalysts show an absorption doublet for adsorbed CO around 2094 and 2075 cm/sup -1/ and bands around 1840 cm/sup -1/ assigned to bridge-bonded CO. Both catalysts show the adsorption of CO/sub 2/ as a carbonate-like species which is demonstrated to be adsorbed onto the support. The effects of reduction temperature and of support material on CO oxidation activity were compared through temperature-programmed reaction experiments. The catalysts reduced at 200/sup 0/C show slightly higher activity and lower ignition temperatures than those reduced at 500/sup 0/C. The rutile-supported catalysts show much higher CO oxidation activity with lower ignition temperatures; the increased activity is speculated to result from a lower activation energy for oxygen desorption. A morphological model of metal-support interactions involving oxygen transfer from the rutile support is proposed to coexist with the Langmuir-Hinshelwood reaction mechanism. 68 references.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 5442142
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 105:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
BINDING ENERGY
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY
HYDROGEN
INFRARED SPECTRA
MATHEMATICAL MODELS
METALS
MORPHOLOGY
NONMETALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PLATINUM
PLATINUM METALS
REDUCTION
SCATTERING
SEPARATION PROCESSES
SORPTION
SPECTRA
SPECTROSCOPY
SURFACE PROPERTIES
SYNTHESIS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY