Temperature dependence of the heterogeneous ferrous-ferric electron transfer reaction rate; Comparison of experiment and theory

Journal Article · Mon Jul 01 04:00:00 EDT 1991 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2085919· OSTI ID:7034953

Curtiss, L A; Hung, N C; Nagy, Z; Yonco, R M ^[1]; Halley, J W; Hautman, J; Rhee, Y J ^[2]

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1. Argonne National Lab., IL (United States). Materials Science and Technology Div.
2. Minnesota Univ., Minneapolis, MN (United States). School of Physics and Astronomy

This paper describes experiments on the temperature dependence of the rate of the ferrous-ferric electron transfer reaction at a gold electrode and compare them with a detailed molecular dynamics simulation which is used to predict the rate. We find from the experiments that the temperature dependence of the rate has the Arrhenius form over the temperature range from 25 to 275{degrees} C, and that the transfer coefficient is independent of temperature in this range. The molecular dynamics simulations are used to two ways to extract activation energies and transfer coefficients for comparison with experiment. In one of these methods, we assume parabolic dependence of the energies for the product and reactant in a reaction coordinate which is not specified a priori. In the other method, we use a quantum mechanical calculation extrapolated from the very short molecular dynamics time scale to times characteristic of the electron transfer rate. The assumption of parabolic dependence of the energies gives an estimate for the activation energy which is consistent with experiment. The transfer coefficient calculated using this assumption is also consistent with experiment.

• DOE Contract Number: FG02-84ER45173; W-31109-ENG-38
• OSTI ID: 7034953
• Journal Information: Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 138:7; ISSN JESOA; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

661100 -- Classical & Quantum Mechanics-- (1992-)
664100* -- Theory of Electronic Structure of Atoms & Molecules-- (1992-)
664400 -- Experimentally Derived Information on Atomic & Molecular Properties-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ACTIVATION ENERGY
CHEMICAL REACTION KINETICS
DATA
ELECTRODES
ELECTRON TRANSFER
ELEMENTS
ENERGY
EXPERIMENTAL DATA
GOLD
INFORMATION
IRON
KINETICS
MATRIX ELEMENTS
MECHANICS
METALS
MOLECULAR ORBITAL METHOD
NUMERICAL DATA
QUANTUM MECHANICS
REACTION KINETICS
TEMPERATURE DEPENDENCE
TRANSITION ELEMENTS