Plasmon‐Assisted Tandem Electrocatalysis for CO ₂ ‐to‐C ₂ H ₅ OH Conversion

An Ag@AgCu core@satellites electrocatalyst, structured with AgCu alloyed nano-islands dispersed at metallic Ag core surface, was designed to reveal the plasmon-assisted tandem electrochemical CO₂ reduction reaction (ECO₂RR) for selective C₂H₅OH production. As unraveled by in situ spectral investigations and theoretical calculations, the core@satellites microstructure enables the tandem ECO₂RR pathway to happen at the interfaced Ag and AgCu sites to facilitate C₂H₅OH formation, with Faradaic efficiency (FE) for C₂H₅OH reaching 61.4% at -100 mA cm^-2. Under light, an intensive localized electric field could be excited in the near-surface region of Ag@AgCu core@satellites, contributing to the increased surface *CO coverage, lowered *COCOH formation barrier and deceased *CHCOH-to-C₂H₅OH conversion free energy. Thus, a high C₂H₅OH selectivity (FE = 65.5%) at industrial-level current density (-280 mA cm^-2) was achieved over Ag@AgCu core@satellites in a photo-electrochemical flow cell.