Isomerization and hydrogenation of cis-2-butene on Pd model catalyst

Journal article

Publication Details

Author(s): Brandt B, Fischer JH, Ludwig W, Libuda J, Zaera F, Schauermann S, Freund HJ
Journal: Journal of Physical Chemistry C
Publication year: 2008
Volume: 112
Journal issue: 30
Pages range: 11408-11420
ISSN: 1932-7447
eISSN: 1932-7455


The adsorption and kinetics of conversion of cis-2-butene with deuterium on model supported Pd catalyst (Pd/Fe3O4/Pt(111)) were characterized by reflection-absorption infrared spectroscopy (RAIRS), temperature-programmed desorption (TPD), and isothermal molecular beam (MB) experiments. It was found that selectivity toward cis-trans isomerization and hydrogenation depends critically on the nature of the carbonaceous deposits, which are typically present during reaction on real catalysts. At low temperatures (190-210 K) both reaction pathways were found to proceed on the initially clean surface, but the catalytic activity was observed to quickly vanish, presumably because of the accumulation of hydrocarbon species on the surface. At temperatures above 250 K, on the other hand, a sustained catalytic activity toward cis-trans isomerization was observed over long periods of time. Interestingly, no catalytic activity could be sustained for the competing hydrogenation on the initially clean catalyst even at these temperatures. Only when highly dehydrogenated carbonaceous fragments were preadsorbed on the surface was it possible to induce a persistent catalytic activity for the hydrogenation (and also the isomerization) of the alkene on our supported palladium particles. Possible reasons of this unique vacuum catalytic behavior are discussed, including different spatial requirements for the competing reaction pathways and changes in the adsorption state of deuterium on and beneath the surface modified by the carbonaceous deposits.

FAU Authors / FAU Editors

Libuda, Jörg Prof. Dr.
Professur für Physikalische Chemie

External institutions with authors

Fritz-Haber-Institut der Max-Planck-Gesellschaft (FHI)
University of California, Riverside (UCR)

How to cite

Brandt, B., Fischer, J.-H., Ludwig, W., Libuda, J., Zaera, F., Schauermann, S., & Freund, H.-J. (2008). Isomerization and hydrogenation of cis-2-butene on Pd model catalyst. Journal of Physical Chemistry C, 112(30), 11408-11420.

Brandt, Bjoern, et al. "Isomerization and hydrogenation of cis-2-butene on Pd model catalyst." Journal of Physical Chemistry C 112.30 (2008): 11408-11420.


Last updated on 2019-06-08 at 09:05