Ab-Initio Modeling of the Electrochemical Potential Effect in Facilitating Heterogeneous Reactions on Catalysts Surface

Abstract

Theoretical modeling of the effect of electrochemical potential on reaction rate will be presented. Using ab-initio Density Functional Theory (DFT), adsorption and dissociation energies are calculated at the atomistic level for the model ethylene oxidation reaction on a ruthenium oxide slab RuO2 (110). Using the surface charging method, known as grand-canonical DFT, the number of electrons is changed on the slab surface to mimic an electrochemical potential application and thus a change in the work function of the surface. Next, a fitted curve is found for the calculated adsorption energies as a function of the changed potential. A similar approach is used for the calculation of dissociation energies (using minimum energy pathway MEP method). The end models showed an electrochemical potential effect on the adsorption energy of reactants as well as on their dissociation energy. This type of modeling helps us understand on the atomistic level what occurs on the surface of a catalyst in a heterogeneous type of reaction under the effect of an electrochemical potential.