Constant current and constant potential electrolyses of oxalic and oxamic acids were carried out on multiwalled carbon nanotubes (CNT) and on monometallic (Pd and Pt) and bimetallic (Ru-Cu) catalysts supported on multiwalled carbon nanotubes. Both carboxylic acids were mineralized with high conversions via hypochlorite ion produced in situ, in 0.10 M NaCl medium. Highest current efficiency, corresponding to 97%, and highest reaction rate constant for oxalic acid mineralization were obtained for the Ru-Cu/CNT modified electrode, in 0.10 M NaCl medium. The mineralization of oxamic acid was achieved with a faradic yield of 96% and an energy consumption of 14.6 kWh (kg of pollutant)(-1) the same medium. The conversion values obtained for the oxidation of oxalic acid in 0.50 M NaOH medium, on Pt/CNT, Pd/CNT and Ru-Cu/CNT modified electrodes, were respectively 42%, 60% and 85%. In this last medium, 88% of the initial oxamic acid (15.8 mM) was transformed to carbonate ion and nitrogen at Pt/CNT modified anode. (C) 2013 Elsevier B.V. All rights reserved.