Spectroscopic evidences of the presence of hydrogenated species on the surface of copper during CO2 electroreduction at low cathodic potentials

The electrochemical reduction of CO2 on a copper electrode in 1-n -butyl-3-methyl imidazolium tetrafluoroborate (BMI.BF4 ) monitored by surface-enhanced Raman scattering (SERS)

“…The features at 2112 and 2072 cm −1 are assigned to the ν 1 and ν 2 CO stretching modes, respectively, where 1 and 2 stands for CO adsorbed on different surface sites. According to the data relative to the spectroscopy of CO adsorbed on copper surfaces presented as Supporting Information, the observation of two features in the CO stretching region is consistent with the in situ Fourier transform infrared and SERS results on the electrochemical reduction of CO 2 over a copper electrode in aqueous solutions . Both CO features are assigned to CO adsorbed on top (linear, Fig.…”

“…Formic acid or formate was also observed as reduction products of CO 2 on copper, but no SERS signal characteristic of these species was found. Therefore, we tentatively assign the SERS signals at 1598, 1165, 1001, and 778 cm −1 to some unsaturated hydrocarbons formed during the CO 2 reduction at lower potentials, when the first signals from adsorbed CO are observed, that is, at −0.2 V. Similar signals were observed in the SERS spectra during the reduction of CO 2 on a copper electrode in water solution . Probably, the Cu 2 O thin film present on the copper surface is favoring this reduction process …”

“…Batista and Temperini attributed these SERS signals to the presence of unsaturated hydrocarbons and CO‐containing hydrocarbons on the copper surface.…”

Selective Electroreduction of CO2 toward Ethylene on Nano Dendritic Copper Catalysts at High Current Density

“…A control and storage mechanism is therefore required which could equalize the delivered excess energy on relatively short time scales to make the energy provided usable. [16,17] It is further unclear which pathways lead to the formation of alcohols such as ethanol, propanol, and methanol. Therefore carbon capture and utilization concepts have been discussed, such as power-to-gas, where the temperature level is a key determinant of energy input.…”

Impurity Ion Complexation Enhances Carbon Dioxide Reduction Catalysis

“…Based on these hypotheses, contemporary strategies to prolonging catalyst lifetimes include periodic oxidative pulsing of the electrode to remove adsorbed organics [32][33][34] and long-term (>9 hrs) pre-electrolysis using a sacrificial electrode to scavenge trace metal ion impurities in the electrolyte. 35 The former is impractical because it progressively alters the catalyst surface structure 42 , and pre-electrolysis has been shown, in many cases, to be ineffective 43,44 and irreproducible, 33,34 and is both energy and time intensive. We note that high surface electrodes 37,38,44,45 should exhibit reduced sensitivity to trace impurities, but these systems are difficult to probe mechanistically, due to their complex morphology and structure.…”