Climate change concerns have spurred a growing interest in developing environmentally friendly technologies for green energy generation (i.e. green H2 from water splitting) and storage in the form of chemical bonds. The latter includes the re-utilization of CO2 via its electrochemical reduction into value-added chemicals and fuels. It is therefore of particular interest to develop efficient, selective and durable electro-catalysts that can operate under mild reaction conditions. Nonetheless, in order to tailor the chemical reactivity of nanocatalysts, fundamental understanding of their structure and surface composition under reaction conditions must be obtained. It should also be kept in mind that even morphologically and chemically well-defined pre-catalysts will be susceptible to drastic modifications under operation, especially when the reaction conditions themselves change dynamically.

This talk will offer new insights into the electrocatalytic reduction of CO2 as well as the oxygen evolution reaction (OER) using model pre-catalysts ranging from single atoms, nanoparticles, thin films to single crystals. Some of the aspects that will be discussed include: (i) the design of size- and shape-controlled pre-catalysts (Cu2O cubes, (ZnO)-Cu2O cubes, (Fe-)CoOx NPs, (Fe-)NiOx) and thin films (NiOx, Co3O4, Co1+δFe2-δO4), (ii) the understanding of the active state formation and (iii) the correlation between the dynamically evolving structure and composition of the electro-catalysts under operando reaction conditions and their activity and selectivity.

These results are expected to open up new routes for the reutilization of CO2 through its direct conversion into industrially valuable chemicals and fuels such as ethylene, and ethanol and the generation of green H2 through water splitting.