pH dependent CO adsorption and roughness-induced selectivity of CO 2 electroreduction on gold surfaces

The Importance of Acid–Base Equilibria in Bicarbonate Electrolytes for CO2 Electrochemical Reduction and CO Reoxidation Studied on Au(hkl) Electrodes

“…The Q Ox scales linearly with the , suggesting that both oxidation peaks (1 st and 2 nd ) can be attributed to a product of CO2RR. For this reason, we investigated whether the origin of the early oxidation wave may relate to the formation of a CO2RR products beyond CO, as proposed by Narayanaru et al 48 During CO2RR on a gold electrode, formic acid (HCOOH) was generally detected with low Faraday efficiency (<5%). 49 − 52 Additionally, a few reports have claimed that at more negative potential CO 2 could even be reduced to methanol (CH 3 OH) 48 , 52 through a path involving the formation of a formaldehyde intermediate (H 2 CO), as calculated by DFT.…”

Nitrogen and sulfur dual-doped high-surface-area hollow carbon nanospheres for efficient CO2 reduction

“…Numerous catalysts have been extensively investigated for CO2RR, such as noble metals (e.g., Ag, Au, Pt, and Pd) [8][9][10][11], alloys (Pt-Au, Au-Cu, and Pd-Sn) [12][13][14], metal oxides (CuO, SnO2, and Bi2O3) [15][16][17], and metallic complexes (Ru, Ir, and Pd complexes) [18][19][20]. These electrocatalysts are capable of reducing CO2 to various products through a multi-electron transfer process, including CO, HCOOH, CH4, high-order hydrocarbons, and oxygenates [21][22][23].…”

Understanding the Voltammetry of Bulk CO Electrooxidation in Neutral Media through Combined SECM Measurements

“… 10 − 12 Recently, CO oxidation on these two surfaces has been used in rotating ring disc electrodes (RRDE), 13 − 15 scanning electrochemical microscopy (SECM), 16 , 17 and cyclic voltammetry 18 experiments for in situ probing the products of CO 2 reduction (CO2R) or the interfacial pH. In these studies, mostly carried out in neutral media, two distinct or convoluted peaks have been observed in the CO oxidation voltammetry, 13 , 14 , 16 − 18 but their assignment is unclear. While the oxidation of a CO adlayer has been extensively studied on mono and polycrystalline platinum at different pH, there are no reports elucidating the mechanism of CO bulk oxidation on platinum in neutral media.…”

“…Using platinum cyclic voltammetry to determine CO2R products is a relatively new approach. Narayanaru et al 16 used a platinum ultramicroelectrode (Pt-UME) in the substrate generation-tip collection (SG-TC) mode of SECM to probe the products of CO2R on gold in 0.1 M KHCO 3 electrolyte. Two distinct CO oxidation peaks were observed in the Pt-UME voltammetry when the gold sample was held at −1.3 V vs Ag/AgCl.…”