Preference for vibrational over translational energy in a gas-surface reaction.
State-resolved gas-surface reactivity measurements revealed that vibrational excitation of nu3 (the antisymmetric C-H stretch) activates methane dissociation more efficiently than does translational energy. Methane molecules in the vibrational ground state require 45 kilojoules per mole (kJ/mol) of translational energy to attain the same reactivity enhancement provided by 36 kJ/mol of nu3 excitation. This result contradicts a key assumption underlying statistical theories of gas-surface reactivity and provides direct experimental evidence of the central role that vibrational energy can play in activating gas-surface reactions.
Smith
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Department of Chemistry and W. M. Keck Foundation Laboratory for Materials Chemistry, Tufts University, Medford, MA 02155, USA.
Killelea
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DR
DelSesto
D F
DF
Utz
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AL