TY - JOUR
T1 - Analytical approach for estimating kinetics of elementary steps on transition metals
T2 - Tunneling, trends and Brönsted-Evans-Polanyi relation
AU - German, E. D.
AU - Sheintuch, M.
N1 - Funding Information:
This paper is dedicated to Alexander Kuznetsov. The long standing history of the quantum kinetics of charge transfer reactions in a polar medium and on solid/solvent interface and related problems owes its success to seminal and long-lasting contribution of Alexander Kuznetsov. One of us, (EG), had a great pleasure to work in his group in Moscow (Institute of Electrochemistry) and then after 1995 to continue the contacts by Internet, and very grateful to Alexander Kuznetsov for his useful discussions and for gentle and pleasant but persistent way of cooperation. This work is supported by Israel-US BSF.
PY - 2011/9/15
Y1 - 2011/9/15
N2 - An overall formulation of an adiabatic approach, which combines adsorption characteristics of reactants and products with an analytical method of searching for the saddle point (SP) on semi-empirical adiabatic potential energy surface (APES), is presented for studying surface reactions kinetics. The following cases are analyzed: (i and ii) breaking or formation of a chemical bond, (iii) diffusion hopping of a molecule on a metal surface, and (iv) subsurface penetration of a metal surface. Numerical results for the activation energies and rate constants of elementary steps of CO oxidation, oxygen dissociative adsorption and water dissociation on transition metals (Pt, Pd, etc.) at the zero-coverage limit are presented. Specifically, the reaction energy dependencies of the kinetic characteristics like activation energy are presented as Brönsted-Evans-Polanyi relation. Moreover, the effect of tunneling along reaction coordinate is shown to be significant for several steps. The calculated diffusitivities of CO on (1 1 1) surfaces of several metals are correlated with the corresponding adsorption energies. The mechanism of subsurface oxygen penetration in a cluster resembling a (1 1 1) palladium surface is investigated. Approximate dependence of the activation energy of the oxygen subsurface diffusion on surface coverage is suggested.
AB - An overall formulation of an adiabatic approach, which combines adsorption characteristics of reactants and products with an analytical method of searching for the saddle point (SP) on semi-empirical adiabatic potential energy surface (APES), is presented for studying surface reactions kinetics. The following cases are analyzed: (i and ii) breaking or formation of a chemical bond, (iii) diffusion hopping of a molecule on a metal surface, and (iv) subsurface penetration of a metal surface. Numerical results for the activation energies and rate constants of elementary steps of CO oxidation, oxygen dissociative adsorption and water dissociation on transition metals (Pt, Pd, etc.) at the zero-coverage limit are presented. Specifically, the reaction energy dependencies of the kinetic characteristics like activation energy are presented as Brönsted-Evans-Polanyi relation. Moreover, the effect of tunneling along reaction coordinate is shown to be significant for several steps. The calculated diffusitivities of CO on (1 1 1) surfaces of several metals are correlated with the corresponding adsorption energies. The mechanism of subsurface oxygen penetration in a cluster resembling a (1 1 1) palladium surface is investigated. Approximate dependence of the activation energy of the oxygen subsurface diffusion on surface coverage is suggested.
KW - Adiabatic approach
KW - Brönsted-Evans-Polanyi relation
KW - Surface reactions
KW - Tunneling
UR - http://www.scopus.com/inward/record.url?scp=80053100017&partnerID=8YFLogxK
U2 - 10.1016/j.jelechem.2010.09.021
DO - 10.1016/j.jelechem.2010.09.021
M3 - 文章
AN - SCOPUS:80053100017
SN - 1572-6657
VL - 660
SP - 261
EP - 275
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
IS - 2
ER -