Theory and modeling electrochemical thermodynamics and kinetics: The Grand Canonical Approach

Electrochemical reactions take place at electrified solid-liquid interfaces. Experimentally the properties of such interfaces are controlled by the temperature, electrolyte and electrode potential. For this set of control variables, the most natural state variables are those of the grand canonical: temperature, electrochemical potential of the electrolyte, and the chemical potential of the electrons. In my contribution I will present how density functional theory can be formulated, implemented and utilized in the grand canonical ensemble to yield free energies at fixed electrolyte/electron chemical potentials. Furthermore, I will present a a general rate theory based on the grand canonical ensemble to provide a unified framework for computing reaction rates at fixed potentials.