Modulating the Hydrogenation Mechanism of Electrochemical CO₂ Reduction Using Ruthenium Atomic Species on Bismuth

Abstract

The conversion of CO2 into formate through electrochemical methods is emerging as an elegant approach for industrial‐scale CO2 utilization in the near future. Although Bismuth (Bi)‐based materials have shown promise thank to their excellent selectivity, their limited reactivity remains a challenge. Herein, this study demonstrates a significant enhancement in the CO2‐to‐formate efficiency of Bi by incorporating ruthenium (Ru) atomic species. Ru single atom doped Bi exhibited a nearly twofold higher partial current density compared with pure Bi and Ru clusters doped Bi, while over 95% Faradaic efficiency (FE) is maintained. Through comprehensive investigations using a combined approach of electrochemical techniques, operando spectroscopy, and theoretical calculations, this study elucidates that the presence of Ru single atom promotes H2O dissociation and H* migration to Bi sites for CO2‐to‐formate conversion by significantly reducing the energy barrier via a H* spillover path. Besides, it is constructed Ru–Bi bridge sites for efficient CO2 hydrogenation via a non‐spillover path, which served as the major mechanism for CO2‐to‐formate conversion in Ru single atom doped Bi.