The electrochemical reduction of deoxybenzoin at the HDME has been studied as a function of pH. Electrodimerization occurs in strongly acidic and basic media which gives rise to either the neutral or the dianionic forms of the dimer, respectively. In the 7.5-9.5 pH range, an alcohol is formed by a two-electron, two-proton irreversible charge transfer. It is shown that transitions between these three simple cases occur through kinetically controlled protonation steps. A chronoamperometric analysis has been implemented to estimate the kinetics of the surface protonation that precedes the electron transfer step in the 4-7 pH range. Digital simulation has been used to characterize the competitive processes that lead to either the alcohol or the dianionic dimer in the 9.5-12 pH range.