Tuning Sb Atoms on Cu-Based Catalysts for Electrochemical Conversion of CO₂ to Syngas

The electrochemical CO₂RR into syngas provides an attractive way to produce raw materials for synthesizing various value-added chemicals. However, a wide range of tunable syngas ratio of CO/H₂ is hard to achieve during the electrochemical CO₂ conversion process. Herein, we propose a facile electrodeposition method for the preparation of Sb modified Cu-based catalysts with a high activity for the ratio-tunable production of syngas. The Cu₁₀Sb₁ catalyst reaches a high FE of 71% for CO at a potential of −1.09 V versus RHE with the tunable CO/H₂ ratio of syngas from ∼0.6 to ∼7.8 at the applied potentials from −0.78 V to −1.09 V. Theoretical calculations reveal the tuning effect of Sb atoms on Cu-based catalyst for the electrochemical conversion of CO₂ to syngas, in which the formation of CO on Sb modified Cu-based catalyst possesses lower energy barrier in potential-limiting steps during CO₂RR. Meanwhile, the robust charge interaction between COOH* species and the surface of Sb modified Cu-based catalyst enhances the activity of COOH* species, thus improving FE and current density for conversion into syngas products. This work brings a new strategy for the synthesis of low-cost syngas catalyst and the tuning effect of metal atom on Cu-based catalyst for CO₂RR.