Preparation of cobalt(III)-EDTA complex without a catalyst? st

I know that I can prepare the complex using a divalent salt, surface active catalyst(i.e.activated carbon) and or atmospheric oxygen and or hydrogen peroxide. What I would like to know, if anyone knows, if I can fully convert cobalt(II) to cobalt(III) without using activated carbon and if so, how long (hours) and under each control condition of temperature, pH, time,etc? Also, if I can't expect 100% yield, how much? This will be an industrial (commercial) synthesis and I don't want to use activated carbon unless absolutely necessary for reasons of added cost and handling (activated carbon is difficult to wet).