Direct C2O4 2-oxidation at a GC electrode (red curve in Figure ) first follows an ECE mechanism, eqs 5-7, corresponding to the first voltammetric wave beginning near E = -0.50 V. As CO2 is generated from C2O4 2-oxidation, C2O4 2-•CO2 forms in solution via eq 8, resulting in the appearance of a second oxidation wave near 0 V that is described by eqs 9 and 10 followed by eqs 6 and 7.