Evidence for low-pressure catalysis in the gas phase by a naked metal cluster: The growth of benzene precursors on Fe[sub 4][sup +]

Journal Article · Thu Nov 28 04:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100177a018· OSTI ID:6837360

Schnabel, P; Irion, M P; Weil, K G ^[1]

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1. Technische Hochschule Darmstadt (Germany)

Chemical reactions of thermalized bare Fe[sub n][sup +] cluster ions (n = 2-13) with ethylene and cyclopropane were studied in a FT-ICR mass spectrometer. The reactivities of Fe[sub n][sup +] cluster ions toward both gases show a pronounced size effect. With ethylene, only Fe[sub 4][sup +] and Fe[sub 5][sup +] react, whereas all the other cluster ions are completely unreactive under the same experimental conditions. In the case of cyclopropane, reactions are observed with Fe[sub 3][sup +], Fe[sub 4][sup +], and Fe[sub 5][sup +]. With both gases, Fe[sub 4][sup +] forms reaction products of stoichiometry Fe[sub 4]C[sub 6]H[sub 6][sup +]. Low-energy collision-induced dissociation (CID) of these reaction products suggests that the carbon and hydrogen atoms on the Fe[sub 4][sup +] nucleus are arranged in such a manner that all 12 atoms are detached simultaneously. Furthermore, comparison with the results from CID experiments on the precursors of the Fe[sub 4]C[sub 6]H[sub 6][sup +] cluster ions reveals that a dramatic bond weakening of the carbon-cluster bonds occurs when the C[sub 6]H[sub 6] stoichiometry is completed on Fe[sub 4][sup +]. This leads to the assumption that benzene is detached. Apparently, Fe[sub 4][sup +] can act as an active center in a catalytic cycle which yields hydrogen and, by CID, benzene from ethylene and from cyclopropane.

• OSTI ID: 6837360
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:24; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
ALKENES
AROMATICS
BENZENE
CATALYSIS
CATALYTIC EFFECTS
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
CYCLOALKANES
DISSOCIATION
ELEMENTS
ETHYLENE
FLUIDS
GASES
HYDROCARBONS
HYDROGEN
ION CYCLOTRON RESONANCE SPECTROSCOPY
ION SPECTROSCOPY
IONS
IRON COMPOUNDS
MASS SPECTRA
NONMETALS
ORGANIC COMPOUNDS
SPECTRA
SPECTROSCOPY
STOICHIOMETRY
TRANSITION ELEMENT COMPOUNDS