“The development of cheaper and more efficient catalysts is necessary to make water electrolysis cost competitive with the fossil fuel based methods currently used for hydrogen production. In particular, the oxygen evolution reaction (OER) of the water splitting process suffers from slow kinetics and impractically large over potentials when operated in neutral aqueous media, which is the ideal environment for cost effective electrolyser construction and running conditions.
We have developed a series of OER catalysts that are composed of closely proximate, co-located, Ca and Mn oxide species layered on a graphene based material. The graphene layer can additionally be functionalized with an organic moiety to aid electron transport and conduct the electrons between the catalyst and the electrolytic circuit. When layered on a suitable substrate this composite material facilitates the electrolytic oxidation of water and can be used as the anode in an electrolytic cell. Using a model electrochemical cell (with a Pt cathode) we have demonstrated that this system has the lowest over-potential for electrolytic water splitting in neutral pH (~ 1.3V vs Ag/AgCl), of any existing synthetic system, that we are aware of.”