A surface enhanced Raman scattering study of the intermediate and poisoning species formed during the electrochemical reduction of CO2 on copper

Surface enhanced Raman scattering (SERS) has been used to study the electrochemical reduction of CO2 on the copper electrode surface. The effect of different oxidation reduction cycles (ORCs) on the observed SERS has been investigated. A modification of the ORCs has been used to create sites which provide stable SERS, allowing exploration of the mechanism of CO2 reduction. The experimental conditions required to observe SERS in this system are described. The time-dependent decay of the SERS bands and the time-dependent increase of a new band, attributed to the formation of a poisoning species, have been measured the intermediate species is CO2 the poisoning species is a copper oxide patina.