Infrared spectroscopy of adsorbed carbon monoxide on platinum/nonacidic zeolite catalysts

Journal Article · Tue Jun 01 00:00:00 EDT 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1155· OSTI ID:6251481

Lane, G S; Miller, J T; Modica, F S; Barr, M K ^[1]

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1. Amoco Oil Company, Naperville, IL (United States)

Infrared spectroscopy of adsorbed carbon monoxide was investigated on a series of platinum (or palladium) zeolite catalysts plus platinum on silica. The platinum catalysts all showed a strong absorbance band around 2070 [plus minus] 20 cm[sup -1] due to linear-bonded CO and a weaker band around 1850 [plus minus] 20 cm[sup -1] due to bridge-bonded CO. Four platinum catalysts, Pt/K[sup +] LTL, Pt/K[sup +] MFI, Pt/K[sup +] MTW, and Pt/K[sup +] SiO[sub 2], had an additional absorbance near 1970 cm[sup -1]. The additional band is not observed for Pt/silica, Pt/La[sup +3] LTL, or platinum supported on H[sup +] LTL or H[sup +] MFI, i.e., neutral and acidic supports. The additional band on the alkalized catalysts is speculated to result from an electrostatic attraction of linear-bonded CO with an alkali cation when Pt is on a nonacidic support. The electrostatic attraction increases the CO adsorption strength and lowers the stretching frequency. The additional linear CO absorption band was also observed on Pd/K[sup +] LTL. The additional infrared band suggests a [open quotes]new type of metal (catalytic) site,[close quotes] no relation was found between the catalytic activity or selectivity for n-hexane dehydrocyclization and the additional CO absorbance band. 49 refs., 6 figs., 6 tabs.

• OSTI ID: 6251481
• Journal Information: Journal of Catalysis; (United States), Vol. 141:2; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HEXANE
DEHYDROCYCLIZATION
PALLADIUM
ABSORPTION SPECTROSCOPY
CATALYTIC EFFECTS
PLATINUM
SILICA
ZEOLITES
ADSORPTION
CARBON MONOXIDE
CATALYST SUPPORTS
CATALYSTS
STRUCTURAL CHEMICAL ANALYSIS
ALKANES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
METALS
MINERALS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
SILICATE MINERALS
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SPECTROSCOPY
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties