Cathodic cleavage of organic compounds at electrodes modified by polyfluorenes or polydibenzofuran is discussed and analyzed by means of cyclic voltammetry and spectroelectrochemistry. The catalytic efficiency, expressed in terms of the potential shift found with such modified electrodes is found to be a function of the nature of the organic compound and the polymer electrode modifier. The use of different polymers as electrode modifiers for macroelectrolysis is also described.