Mode-specificity and transition state-specific energy redistribution in the chemisorption of CH4 on Ni{100}

Abstract

We have investigated methane (CH₄) dissociative chemisorption on the Ni{100} surface by first-principles molecular dynamics (MD) simulations. Our results show that this reaction is mode-specific, with the ν₁ state being the most strongly coupled to efficient energy flow into the reaction coordinate when the molecule reaches the transition state. By performing MD simulations for two different transition state (TS) structures we provide evidence of TS structure-specific energy redistribution in methane chemisorption. Our results are compared with recently reported state-resolved measurement of methane adsorption probability on nickel surfaces, and we find that a strong correlation exists between the highest vibrational efficacy measured on Ni{100} for the ν₁ state and the calculated highest fractional vibrational energy content in this mode.