Steering CO₂electroreduction selectivity towards CH₄and C₂H₄on a tannic acid-modified Cu electrode

Abstract

The CO2 electroreduction (CO2RR) offers a promising way to address CO2 emission and high-value ultilizaiton but it remains challenging to steer the selectivity of products due to complicated reaction pathways....

Pd-Decorated Cu2O–Ag Catalyst Promoting CO2 Electroreduction to C2H4 by Optimizing CO Intermediate Adsorption and Hydrogenation

“… Further, to evaluate the CO 2 RR selectivity, a series of chronoamperometry measurements for Cu 2 O, Cu 2 O–Ag, Cu 2 O–Pd, and Cu 2 O–Pd–Ag catalysts were performed in a CO 2 -saturated 0.5 M KHCO 3 electrolyte (Figure S16). As shown in Figures b and S17, the Cu 2 O–Pd–Ag ternary catalyst exhibits the highest selectivity for C 2 H 4 , and the FE C 2 H 4 for Cu 2 O–Pd–Ag reaches 63.2% at −1.2 V vs RHE, much higher than that of Cu 2 O (39.3%), Cu 2 O–Ag (51.4%), and Cu 2 O–Pd (53.1%) at their optimal potentials, and also, higher than most of the reported catalysts (Figure c). ,− Meanwhile, Cu 2 O–Pd–Ag exhibits a wider potential window, and the FE C 2 H 4 could be maintained above 58% at −1.1 to −1.3 V vs RHE. To investigate the catalyst activity for C 2 H 4 production, the C 2 H 4 partial current density ( j C 2 H 4 ) and the overpotential of C 2 H 4 production were calculated.…”

Water clustering modulates activity and enables hydrogenated product formation during carbon monoxide electroreduction in aprotic media

“…License: CC BY-NC-ND 4.0 of water in the mechanism towards CORR products such as ethylene and methane. For aqueous CO2RR, pc-Cu catalysts yield KIE of around 2 for ethylene 62,63 and 2.3 for methane. 62 These KIE values were attributed towards water dissociation on Cu(100).…”

“…For aqueous CO2RR, pc-Cu catalysts yield KIE of around 2 for ethylene 62,63 and 2.3 for methane. 62 These KIE values were attributed towards water dissociation on Cu(100). 64 These works decreased the ethylene KIE closer to 1 through using tannic acid or halogen modification that activates water so that water dissociation is less involved in the RDS.…”

“…For the microheterogeneous solvents, the KIE for methane differs with values from 2 to 1.5 for ACN, with increasing water mole fraction and a reverse KIE effect that increases to approximately 1 for THF. The higher KIE values for ACN could correspond to water dissociation, 62 indicating that neutral water is the main source of protons for methane formation. The inverse isotope effect observed for THF suggests that acidic protons, H + , 65 are the primary proton source for methane production.…”