Chemists in Leiden have established a set of guidelines that can lower the oxidation potential of copper-catalysed water oxidation, according to a paper in the European Journal of Inorganic Chemistry.

If you want to produce hydrogen electrochemically, you will probably have to use the water splitting reaction. But without catalysts based on expensive and scarce metals, the half reaction of oxidising water remains a challenge. If you want to use the cheaper metals from the fourth row of the periodic table (Ni, Fe, Cu), then choosing the right ligand is essential. Daan den Boer, Dennis Hetterscheid and colleagues at Leiden University have used a number of variants of a ligand to see how the changes affect the water oxidation reaction.