Influence of preparation method on the metal cluster size of Pt/ZSM-5 catalysts as studied with extended x-ray absorption fine structure spectroscopy

Journal Article · Thu Nov 15 00:00:00 EST 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100386a017· OSTI ID:6084159

Kampers, F W.H. ^[1]; Engelen, C W.R. ^[2]; van Hooff, J H.C.; Koningsberger, D C ^[3]

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1. DLO/TFDL Technical and Physical Engineering Science for Agricultural Research, Wageningen (Netherlands)
2. EXXON Chemicals Holland B.V., Rotterdam (Netherlands)
3. Eindhoven Univ. of Technology (Netherlands)

The size of Pt particles introduced into the channels of ZSM-5 zeolite by two different preparation methods has been studied with EXAFS. ZSM-5 was loaded with 2 wt % Pt by ion exchange and by impregnation. By careful calcination of the catalysts the dispersion was maintained. The EXAFS measurements were performed on the reduced system. Analysis of the data showed that in the impregnated sample the platinum was present in particles which on average were smaller than the platinum particles in the ion-exchanged sample. These results corroborate earlier high-resolution electron microscopy measurements performed ex situ on the calcined catalysts. Moreover, the average particle size found from EXAFS analysis agrees well with the HREM results, indicating that dispersion is maintained during reduction. Both techniques indicate particles that exceed the dimensions of a zeolite cage at the intersection of the channels.

• OSTI ID: 6084159
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 94:23; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ZEOLITES
ABSORPTION SPECTROSCOPY
MICROSTRUCTURE
CATALYSTS
CHEMICAL PREPARATION
EXPERIMENTAL DATA
PLATINUM
X-RAY SPECTROSCOPY
CRYSTAL STRUCTURE
DATA
ELEMENTS
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
METALS
MINERALS
NUMERICAL DATA
PLATINUM METALS
SPECTROSCOPY
SYNTHESIS
TRANSITION ELEMENTS
360601* - Other Materials- Preparation & Manufacture
360602 - Other Materials- Structure & Phase Studies