In most electrochemical (EC) systems, the coupled flow of matter and charge across the electrified interfaces (EI) between ionic and electronic conductors converts chemical and electrical forms of energy. However, the detailed theoretical understanding of the basic phenomena occurring at EI is still in its infancy. A prime example in this respect is our limited knowledge of the effect of an external bias applied to the electrolyte through the electrodes.
In this talk we will introduce some issues connected with the simulation of the effect
of an applied potential to an EC cell and present some recent progress in the simulation
of the double layer of a prototypical Pt-water interface and its response to changes of potential applied to the cell.
The system is simulated dynamically, fully from first principles,including charge polarization effects at both sides of the interface, explicit solvent and its rearrangements upon changing the electrode polarization. Varying the relative number of solvated cations and anions provides a way to control the charge on the electrode, controlling, in turn, the applied potential.
A detailed description of the structure of the Pt/water DL is provided, reproducing
the localization of electric field and potential energy drop within a microscopic distance from the metal surface.