The kinetics of ethylidyne formation from ethylene on Pd(111)
Document Type
Article
Publication Date
5-14-2009
Abstract
Recent density functional theory (DFT) calculations of the activation energy for the conversion of ethylene to ethylidyne on Pd(111) (Moskaleva, L. V.; Chen, Z.-X.; Aleksandrov, H. A.; Mohammed, A. B.; Sun, Q.; Rösch, N. J. Phys. Chem. C 2009, 113, 2515) predicted an activation barrier with respect to gas-phase ethylene of ∼46 kJ/mol, substantially lower than the results of previous DFT calculations. Thus, the kinetics of formation of ethylidyne from ethylene on Pd(111) are measured as a function of sample temperature using reflection-absorption infrared spectroscopy to monitor the ethylidyne coverage as a function of time. The results yield an experimental value of the height of the activation barrier with respect to gas-phase ethylene of 49 ± 5 kJ/mol, in good agreement with the results of the DFT calculations. The agreement between experiment and theory indicates that the proposed ethylidyne formation pathway involving an initial, ratelimiting ethylene dehydrogenation step to form vinyl species that finally form ethylidyne via an ethylidene intermediate is correct. © 2009 American Chemical Society.
Publication Title
Journal of Physical Chemistry C
Recommended Citation
Stacchiola, D.,
&
Tysoe, W.
(2009).
The kinetics of ethylidyne formation from ethylene on Pd(111).
Journal of Physical Chemistry C,
113(19), 8000-8001.
http://doi.org/10.1021/jp902158s
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/8132