This proposal is about understanding the atomic-scale structure of complex oxides that contain water or protons and that are used as electrocatalyts for water splitting. Such materials are are highly sought after to meet the demands of energy applications, such as in electrolysers for hydrogen and oxygen production for clean fuels. We are exploring the formation of new oxides to optimise activity, in particular by hydrothermal synthesis, which allows a variety of metals to be included in nanocrystalline oxides that can be made into robust catalysts. To understand why some materials are better than others, we need to build up a comprehensive picture of their structures and to relate this to their synthesis conditions and electrocatalytic activity. The question to address here is the nature of protonic species in the oxides: this we will investigate by inelastic neutron scattering.