The Effect of Phase Transitions , Surface Diffusion , and DAAL 03 - 89 - C - 0038 Defects on Heterogeneous Reactions

Abstract

SThe influence of attracuve absorbate-absorbate interacUons and surface diffusion on phase transitions in unumolecular surface reacuons is examined by Monte Carlo sunulauoos. Detailed studies mn paramet spa= are performed assuming vanom forms of 0 desorpton and reaction rate expressions. Introducuon of rate anomalies can lead either to a kinetic or to an equilibrium phase transition, depending on the reaction kinetics and the rate-determiunin processes. It is demonstrated that migration affects the reaction rate. nuicleauon. and phase transiuons. and. therefore. detailed study of them at a molecular level is necessary to describe heterogenous reactions. Hysteress in reactant coverage and reacuon rate are studied and large fluctuauons are found to dominate the system dynammcs near cusp points. The influence of defects which act as nucleation centers on metastability is also investigated. 00 The Monte Carlo data are compared with the predictions of mean-field theory., and limitations of the latter are discussed

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Cite this paper

@inproceedings{VlachosTheEO, title={The Effect of Phase Transitions , Surface Diffusion , and DAAL 03 - 89 - C - 0038 Defects on Heterogeneous Reactions}, author={Dionisios G. Vlachos and Laurette Schmidt and Rutherford Aris and Vincent Hall Minneapolis} }