Spectroscopic investigation of co-hosted metal and basic nanospecies in Pt/CsBEA catalysts.
|Pascale Massiani 1, Chiara Bisio 2, Katia Fajerwerg 1, Gianmario Martra 2|
1. Laboratoire de réactivité de Surface, CNRS UPMC (LRS), 4 place Jussieu, casier 178, Paris 75252, France
In the field of metal supported heterogeneous catalysis, one advantage of zeolites among other aluminosilicate supports is to be characterized by strongly organized microporous channel systems in which both a high dispersion and a regular distribution of metal nanoparticles can be obtained. Another interest of these supports is the possibility to easily tune their acid-base properties by simply changing their chemical composition, thus possibly modifying the characteristics of the dispersed metal particles through metal-support interaction effects. This will be exemplified in this presentation in which we will show how the particle size and electronic properties of dispersed platinum vary when the basicity of Cs-containing support with BEA zeolite structure increases. Particularly, in samples containing caesium in excess as compared to the exchange capacity of the zeolite, Pt nanoparticles with sizes in the 2-1 nm range (detected by TEM) and even below 1 nm (detected by EXAFS) are formed. Besides other physicochemical techniques, we will focus on the characterization of the supported species in these systems by IR spectroscopy of adsorbed CO, CO2 and N2 probe molecules. This will allow us to describe the processes of formation and interaction upon thermal activation treatments of co-hosted Pt nanoparticles and Cs-oxide like nanospecies with strong basic character.
Presentation: Invited oral at E-MRS Fall Meeting 2006, Symposium B, by Pascale Massiani
See On-line Journal of E-MRS Fall Meeting 2006
Submitted: 2006-05-29 11:12 Revised: 2009-06-07 00:44
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