| Autor: |
Lin, Xuehao, Lambert, Jean-François H., Fripiat, José J., Monthioux, Marc, Oberlin, Agnès |
| Zdroj: |
Catalysis Letters; March 1989, Vol. 3 Issue: 2 p169-177, 9p |
| Abstrakt: |
The kinetics of gas phase hydrogen uptake into platinized VMoO5.5 to form the bronze H-3.2VMoO5.5 is limited by diffusion of atomic hydrogen from Pt crystallites to the mixed oxide (spillover). It is therefore strongly dependent on the precursor platinum salt (H2PtCl6, Pt(NH3)4Cl2 or Pt(NH3)4(OH)2) as well as on the pretreatment conditions between salt deposition and hydrogen exposure, since these parameters determine platinum dispersion. While traditional techniques for metal dispersion measurement, such as CO adsorption or H2 adsorption/titration are inappropriate for this system, semi-quantitative information on Pt dispersion can be extracted from a simple analysis of the kinetics. These dispersion estimates are in reasonably good agreement with average particle sizes obtained from TEM micrographs. |
| Databáze: |
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| Externí odkaz: |
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