Copper(II) catalysis of water oxidation.

Copper leads to a breakup: simple Cu(II) salts are shown to be highly reactive as water oxidation electrocatalysts in neutral to weakly basic aqueous buffer solutions of CO(2)/HCO(3)(-)/CO(3)(2-) or HPO(4)(2-)/PO(4)(3-). Coordination to the buffer anions under these conditions prevents the precipitation of Cu(OH)(2), CuCO(3), or Cu(3)(PO(4))(2) and appears to stabilize higher oxidation states of copper.