Formic acid is a promising compound with regard to hydrogen storage and generation, as it can be formed via the hydrogenation of CO2 and decomposed to form H2 and CO2. The electrochemistry of formic acid, aqueous solutions of ammonium formate, and ammonium formate/formic acid eutectic mixtures (1.0:1.25 mol/mol, respectively) have been investigated. The electrocatalytic oxidation of formic acid was observed in the eutectic mixtures, and bulk electrolysis at platinum electrodes demonstrated electrolysis of the formic acid to form H2 and CO2. © 2010 The Royal Society of Chemistry.