The interaction of propargyl alcohol and allyl alcohol with a platinum (Pt) electrode modified by the presence of reduced CO2 adsorbates (r-CO2) is studied through voltammetry and potentiostatic current transients by using a flow cell technique. The interaction between each alcohol and r-CO2 is promoted at three constant potentials corresponding to different degrees of Pt surface coverage by H-atoms. For both alcohols the anodic stripping peaks and the charge balance are interpreted in terms of the formation of composed adsorbates. Based upon the probable r-CO2 structure and H-bonding interactions between r-CO2 and the alcohol molecules or their adsorbed residues, average alcohol residues/r-CO2 molecular ratios are estimated.