Proceedings of nanoGe Fall Meeting 2021 (NFM21)
Publication date: 23rd September 2021
The CO2 reduction reaction is structure sensitive on Cu electrocatalysts.[1] This means that both electrocatalytic activity and product selectivity will strongly depend on the distribution of different crystallographic domains on the surface of catalyst materials. Blank cyclic voltammograms (CVs) of Cu electrocatalyst surfaces are usually recorded to check the cleanness and surface ordering of the electrocatalyst. However, CVs of more realistic Cu electrodes, such as nanoparticles, nanostructured or poly-faceted electrodes, usually display very small features or are even featureless. Consequently, the blank CVs of the majority of Cu surfaces offer little information in relation to their structure and ordering. As an alternative to blank CVs in aqueous electrolytes, metal underpotential deposition (UPD) on metallic surfaces has been widely employed for the surface characterization of different kinds of electrodes. Herein, we have evaluated the lead (Pb) underpotential deposition (UPD) on well-defined Cu electrode surfaces in presence of chloride, as a tool to analyse the surface state and determine the presence and distribution of domains on Cu. A polycrystalline Cu electrode was specifically modified by applying different electrochemical pre-treatments. Then, its surface ordering was tested by Pb UPD. Results were compared with Cu single-crystalline electrodes.[2] Figure 1 shows the lead UPD on Cu electrodes in A) 2 mM Pb(ClO4)2+ 0.1M KClO4, pH 3 and B) 2 mM Pb(ClO4)2+1mM NaCl+ 0.1M KClO4, pH 3. CVs are recorded at 5 mV/s