Decomposition of 1,3-butadiene on Ru(001): Evidence for a (CH){sub 4} metallacycle

Journal Article · Sat Jul 01 04:00:00 EDT 2000 · Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films

DOI:https://doi.org/10.1116/1.582367· OSTI ID:20217052

Weiss, Michael J ^[1]; Hagedorn, Christopher J ^[1]; Weinberg, W Henry ^[1]

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1. Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California 93106 (United States)

The adsorption and thermal decomposition of 1,3-butadiene has been studied on Ru(001). Starting with a condensed multilayer at 80 K, the decomposition of 1,3-butadiene was monitored as a function of temperature using temperature programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS). Annealing the multilayer-covered surface to 800 K results in the decomposition of some of the adsorbed 1,3-butadiene, leaving a surface carbon coverage corresponding to 0.67{+-}0.03 carbon adatoms per surface ruthenium atom, as determined by titration with oxygen. As the butadiene decomposes between 230 and 700 K, hydrogen desorbs in an amount corresponding to 1.01{+-}0.05 adatoms per surface ruthenium atom. A HREEL spectrum taken after annealing to 260 K for 10 s provides spectroscopic evidence for the presence of a (CH){sub 4} metallacycle decomposition product. This assignment is consistent with and supported by the determination of a surface stoichiometry of CH{sub 1.04{+-}}{sub 0.11} using TPD spectra. The formation of the catalytically important (CH){sub 4} metallacycle has been predicted theoretically, but this work represents the first experimental evidence for the formation of this intermediate from the decomposition of 1,3-butadiene. (c) 2000 American Vacuum Society.

• OSTI ID: 20217052
• Journal Information: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films, Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films Journal Issue: 4 Vol. 18; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ADSORPTION
ANNEALING
BUTADIENE
CATALYST SUPPORTS
DECOMPOSITION
ENERGY-LOSS SPECTROSCOPY
EXPERIMENTAL DATA
RUTHENIUM
TEMPERATURE DEPENDENCE