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. (C) 2011 Elsevier Ltd. All rights reserved.