Both catalyst systems exhibit an induction period, the length of which decreases with increasing current (middle plot in Figure ). For Co(salen)-1, the induction period is unaffected by increasing catalyst concentration. By contrast, in the Co-bipyridine system, the length of the induction period increases as catalyst concentration increases. The induction period for Co-bipyridine could be removed by pre-activating the catalyst with 0.12 F/mol electrolysis. Deposition of Co on the electrode was also inferred by CV experiments in the absence of substrate. These observations may help to explain the unusual finding of zero-order kinetics in [Co] in the Co-bipyridine case; the active catalyst may be a surface Co species. Further studies are underway to probe these effects.