Iridium-EDTA as an efficient and readily available catalyst for water oxidation.

It′s so easy: The readily available and highly water‐soluble [IrCl(Hedta)]Na complex is an efficient and robust catalyst for water oxidation to molecular oxygen. The reaction is driven by the reduction of Ce4+ to Ce3+. Its performances (TOF=6.8 min−1 and TON>12 000) are derived by UV/Vis spectroscopic, volumetric and electrochemical measurements, and compare favorably with those of the best catalysts reported so far.