Mode-specific reactivity of CH4 on Pt(110)-(1×2): The concerted role of stretch and bend excitation

The state-resolved reaction probability of CH4 on Pt(110)-(1×2) was measured as a function of CH4 translational energy for four vibrational eigenstates comprising different amounts of C-H stretch and bend excitation. State-specific reactivity is observed both between states from different polyads and between isoenergetic states belonging to the same polyad of CH4. For the stretch/bend combination states, the vibrational efficacy of reaction activation is observed to be higher than for either pure C-H stretching or pure bending states, demonstrating a concerted role of stretch and bend excitation in C-H bond scission. This concerted role, reflected by the non-additivity of the vibrational efficacies, is consistent with transition states structures found by ab-initio calculations and indicates that current dynamical models of CH4 chemisorption neglect an important degree of freedom by including only C-H stretching motion.


Published in:
Physical Review -Series B-, 82, 12, 121404(R)
Year:
2010
Publisher:
American Physical Society
ISSN:
1098-0121
Keywords:
Note:
Rapid communication, selected as editors choice by Phys. Rev. B
Laboratories:




 Record created 2010-09-09, last modified 2018-03-17

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