Electrolysis of water on oxide surfaces

In this paper, density functional theory (DFT) calculations are performed to analyze the electrochemical water-splitting process producing molecular oxygen (O2) and hydrogen (H2). We investigate the trends in the electro-catalytic properties of (1 1 0) surfaces of three rutile-type oxides (RuO2, IrO2, and TiO2). The two first of these oxide anodes show lower O2-evolving over-potentials than metal anodes, due to weak O binding but strong hydroxyl (HO∗) binding on the surface. Furthermore, the binding energies of O, HO, and HOO on the (1 1 0) surfaces fulfill universal linear relations similar to those found on metal surfaces.