Values of ns were then measured over a range of C2O4 2-, S2O8 2-, and Ru(NH3)6 3+ concentrations, with the results presented in Figure . With the concentrations of Ru(NH3)6 3+ and S2O8 2-held constant at 0.5 and 1.0 mM, respectively, a decrease in ns from 1.94 ± 0.03 to 0.34 ± 0.01 (Figures and) was observed as the concentration of C2O4 2-increased from 0 to 220 mM. Then, with the concentrations of C2O4 2-and S2O8 2-held constant at 200 and 1.0 mM, respectively, an increase in the concentration of Ru(NH3)6 3+ from 0.25 to 5.0 mM (Figures and) resulted in a decrease in ns from 0.45 ± 0.04 to 0.10 ± 0.04. Finally, at constant values of 3.5 mM Ru(NH3)6 3+ and 200 mM C2O4 2-, decreasing the concentration of S2O8 2-from 10 mM to 0.5 mM resulted in a further decrease in ns from 0.36 ± 0.05 to 0.02 ± 0.09 (Figures and). Thus, within the experimental error of the CPE measurements, these data indicate that the solution conditions can be optimized such that a self-sustaining S2O8 2-/C2O4 2-autocatalytic reaction can be initiated by injection of an vanishingly small number of electrons (i.e., ns ~ 0 within error of the CPE measurement). The potential applied in the CPE experiments, -0.35 V, is ~1.5 V more negative than the potential at which C2O4 2-is electrochemically oxidized to CO2, i.e., E 0 = 1.2 V vs Ag/AgCl, eq 11 and Figure . Thus, C2O4 2-oxidation leading to CO2 generation at the CPE working electrode is not feasible. The use of a divided electrolysis cell also eliminates C2O4 2-oxidation at the counter electrode during electrolysis. Thus, CO2 generation can only occur via the autocatalyic reaction.