Bubble dynamics during Kolbe electrolysis of trifluoroacetic acid at Pt electrodes

The dynamics of gas evolution during Kolbe electrolysis is studied. Trifluoroacetic acid is used as the organic fuel and platinum as a working electrode. The evolution of gas products is examined by potentiodynamic and potentiostatic experiments as well as by electrochemical impedance spectroscopy. It is found that for 0.5 mm or 1 mm electrode diameter the evolution of Kolbe gas products is accomplished by the nucleation, growth and release of a single gas bubble which is evolved periodically, depending on the surface roughness of the platinum electrode.