Electrochemical microcalorimetry at single electrodes

The heat, which is reversibly exchanged at a single electrode, directly correlates with the entropy change during the electrochemical reaction. With recent experimental improvements also surface electrochemical reactions, i.e., reactions with only submonolayer conversion became accessible for heat measurements. Since the reaction entropy includes all side reactions, e.g., also charge–neutral coadsorption or ordering processes of the solvent, it provides complementary information to the current–potential relation, as for example measured by conventional cyclic voltammetry. Here, we will briefly review the theoretical background and recent developments and compare the method to other approaches for the measurement of the entropy of electrochemical systems.