Elucidating Reaction Pathways in CO2 Electroreduction: Case Study of Ag and Cu2O@Ag Catalysts

CO2 electroreduction is a prospective avenue to produce carbon-based fuels, yet atomic-level insights on the mechanistic origin of catalytic selectivity remains elusive. Taking the Ag and Cu2O@Ag electrocata-lysts as examples, Fourier-transform infrared spectroscopy in conjunction with theoretical calculations reveal that the hollow-nanostructured Ag promotes CO production through a lower energy barrier of the rate-limiting *CO2 to *COOH, while the Cu2O-Ag boundaries in the honeycomb-like Cu2O@Ag rein-force CO2 physisorption and chemisorption on the catalyst surface. The interfaces of Cu2O@Ag facilitate CO hydrogenation and CAC coupling, opening alternative reaction pathways toward CH4 and C2H4. More broadly, this study provides insights to develop effective electrocatalysts in CO2 electroreduction and beyond. (c) 2022 Elsevier Inc. All rights reserved.