Single Atom Bi Decorated Copper Alloy Enables C−C Coupling for Electrocatalytic Reduction of CO₂ into C₂₊ Products**

Abstract

Single atom alloy (SAA) catalysts have been recently explored for promotion of various heterogeneous catalysis, but it remains unexplored for selective electrocatalytic reduction of carbon dioxide (CO₂ ) into multi-carbon (C₂₊ ) products involving C-C coupling. Herein we report a single-atomic Bi decorated Cu alloy (denoted as BiCu-SAA) electrocatalyst that could effectively modulate selectivity of CO₂ reduction into C₂₊ products instead of previous C₁ ones. The BiCu-SAA catalyst exhibits remarkably superior selectivity of C₂₊ products with optimal Faradaic efficiency (FE) of 73.4 % compared to the pure copper nanoparticle or Bi nanoparticles-decorated Cu nanocomposites, and its structure and performance can be well maintained at current density of 400 mA cm^-2 under the flow cell system. Based on our in situ characterizations and density functional theory calculations, the BiCu-SAA is found to favor the activation of CO₂ and subsequent C-C coupling during the electrocatalytic reaction, as should be responsible for its extraordinary C₂₊ selectivity.