Catalysts are compounds that speed the rate of a chemical reaction without themselves being altered by it – they can be reused again and again. Electrocatalysts are a special type of catalyst acting at electrode surfaces and facilitating reactions taking place there. With the advent of nanotechnology and the interesting functionalities of nano-scale materials, it is only natural that such materials would find relevance in electrocatalytic applications. European scientists sought to systematically characterise factors affecting activity and selectivity of nanocrystalline oxide electrodes with EU funding of the ‘Nanocrystalline oxides for selective oxidative electrocatalysis’ (NOSOE) project. Scientists focused on so-called oxygen and chlorine evolution reactions (CERs) in acidic solutions. These reactions are used to generate molecular oxygen (O2) and chlorine (Cl2) via electrolysis of acids. In particular, the NOSOE consortium sought to elucidate the mechanisms and active sites (where the catalyst binds the reactant(s)) of oxide electrocatalysts. Knowledge of catalyst action along with the use of advanced synthetic approaches could lead to the development of a new class of oxide-based electrocatalytic materials with controlled activity and selectivity. The consortium optimised synthetic procedures for specific electrocatalysts of interest. They characterised them with advanced X-ray diffraction techniques and tested their activity for oxygen and chlorine evolution in acidic media.The catalysts were highly selective for oxygen evolution even at high chloride ion concentrations. Investigators then developed detailed structural models (using X-ray absorption spectroscopy) including distribution and bonding arrangements of certain chemical species as well as prospective active sites on the oxide catalyst surface. Results of the NOSOE project have been presented in international journals and at international conferences. They are expected to have important impact on development of catalysts for fuel cells and to enhance the use of renewable wind and solar energy.