The homogeneous water oxidation catalyst [Co9(H2O)6(OH)3(HPO4)2(PW9O34)3]16− (Co9) maintains its redox activity when incorporated into a solid-state matrix. As part of a modified amorphous carbon electrode, high catalytic water oxidation rates are maintained for hours in a large pH range, including acidic conditions, where classic metal oxides are unstable.
![](https://www.iciq.org/wp-content/uploads/2014/07/13-InorgChem-JRGM-4753.gif)