Détail de la notice
Titre du Document
Dehydrogenation of isopropyl alcohol on carbon-supported Pt and Cu-Pt catalysts
Auteur(s)
RIOUX R. M. ; VANNICE M. A.
Résumé
The kinetics of isopropyl alcohol (IPA) dehydrogenation over carbon-supported Pt and three bimetallic Cu-Pt catalysts were examined and compared with previous results for carbon-supported Cu. Adsorption of H2 and CO, dissociative chemisorption of N2O, and the titration of adsorbed O atoms by H2 and CO were used to determine surface compositions and metal dispersion. Monometallic platinum catalysts had a higher specific activity than monometallic Cu catalysts and the bimetallic catalysts; for example, at 448 K and 14 Torr IPA, for an activated carbon heat treated at 1223 K as the support, the turnover frequency (TOF) on the Pt catalyst was 0.11 s-1, the TOF on the Cu catalyst was 0.020 s-1, and the TOFs on the three bimetallic catalysts were between 0.006 and 0.043 s-1. Reaction orders were typically between 0 and 1/2 for IPA and slightly negative for acetone and H2. Increasing the Cu loading reduced the number of surface Pt atoms, and the kinetic behavior became similar to that of monometallic copper catalysts. The apparent activation energy for acetone production from IPA on Pt/C was 6.8 kcal mol-1, compared with 21 kcal mol-1 for the monometallic Cu/C catalysts. Apparent activation energies for the Cu-Pt/C catalysts (7-9 kcal mol-1) were comparable to those of Pt/C at lower temperatures and decreased further to ∼ 3 kcal mol-1 above 443 K. This decrease is not due to diffusional limitations and can be explai
Editeur
Elsevier
Identifiant
ISSN : 0021-9517 CODEN : JCTLA5
Source
Journal of catalysis (Print) A. 2005, vol. 233, n° 1, pp. 147-165 [19 pages] [bibl. : 114 ref.]
Langue
Anglais
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