Chiral Nanostructured Ag Films for Multicarbon Products from CO₂ Electroreduction

Abstract

The formation of multicarbon products from CO₂ electroreduction is challenging on materials other than Cu-based catalysts. Ag has been known to be a typical metal catalyst, producing CO in CO₂ electroreduction. The formation of C₂₊ products by Ag has never been reported because the carbon-carbon (C-C) coupling is an unfavorable process due to the high reaction barrier energy of *OCCO. Here, we propose that the chirality-induced spin polarization of chiral nanostructured Ag films (CNAFs) can promote the formation of triplet OCCO by regulating its parallel electron spin alignment, and the helical lattice distortion of nanostructures can decrease the reaction energy of *OCCO, which triggers C-C coupling and promotes subsequent *OCCO hydrogenation to facilitate the generation of C₂₊ products. The CNAFs with helically lattice-distorted nanoflakes were fabricated via electrodeposition using phenylalanine as the symmetry-breaking agent. C₂₊ products (C₂H₄, C₂H₆, C₃H₈, C₂H₅OH, and CH₃COOH) with a Faradaic efficiency of ∼4.7% and a current density of ∼22 mA/cm² were generated in KHCO₃ electrolytes under 12.5 atm of CO₂ (g). Our findings propose that the chiral nanostructured materials can regulate the multifunctionality of catalytic performance in the catalytic reactions with triplet intermediates and products.