Tailoring the chemical reactivity of nanomaterials at the atomic level is one of the most important challenges in electro-catalysis research. In order to achieve this elusive goal, we must first obtain a fundamental understanding of the structural and chemical properties of these complex systems. In addition, the dynamic nature of the nanostructured films and nanoparticle (NP) catalysts and their response to the electrochemical environment must be taken into consideration, since their working state might not be the state in which the catalyst was prepared, but rather a structural and/or chemical isomer that adapted to the particular reaction conditions. To address the complexity of real-world electrocatalysts, a synergistic approach taking advantage of a variety of cutting-edge experimental methods (EC-AFM, AP-XPS, XAFS) has been undertaken here.

This talk will focus on model electrocatalysts (Ag, Cu, Cu-M with M = Zn, Ga, Sn, Co, Ni, Au, Ag) for the electrocatalytic reduction of CO₂. We will show how rationally design electrocatalytically active model NPs with narrow size, shape, interparticle distance distributions and tunable oxidation state. Furthermore, we will provide insight into structure/chemical state-reactivity correlations during the electrochemical reduction of CO₂ through an in situ and operando approach under reaction conditions. The results are expected to open up new routes for the reutilization of CO₂ through its direct selective conversion into valuable chemicals and fuels such as carbon monoxide, methane, ethylene, ethanol, and propanol.