(Keynote) Tuning the Activity and Selectivity of CO2 Electroreduction Catalysts through Nanostructuring and Controlled Oxidation

Abstract

CO2 electroreduction (CO2RR) into useful chemicals and fuels is a promising technology that might be utilized to minimize the impact that the increasing industrial CO2 emissions are having on the environment. In this talk I will discuss the use of O2-plasma treatments and pulsed potential CO2 electrolysis for the activation of nanostructured metallic surfaces and the re-generation of surface oxides. Although plasma-oxidized silver surfaces were found to display a considerably decreased overpotential for the production of CO, the hydrogen evolution reaction (HER), a competing reaction against CO2 reduction, was found to increase over time. More stable and C1-product selective SnOx/AgOx catalysts will be presented. Additionally, a direct correlation between the presence of Cu2O on well-defined single crystal and nanostructured Cu surfaces and the enhanced production of C2+ products will be illustrated. Electrochemical tests combined with ex situ SEM/TEM-EDS, quasi in situ XPS, operando EC-AFM and XAFS data will be used to extract correlations between the activity, selectivity and stability of CO2RR catalysts and their morphology, structure, composition, and chemical state.