A Sulfur‐Doped Copper Catalyst with Efficient Electrocatalytic Formate Generation during the Electrochemical Carbon Dioxide Reduction Reaction

Abstract

Catalysts involving post‐transition metals have shown almost invincible performance on generating formate in electrochemical CO2 reduction reaction (CO2RR). Conversely, Cu without post‐transition metals have struggled to achieve comparable activity. In this study, a sulfur (S)‐doped‐copper (Cu)‐based catalyst is developed, exhibiting excellent performance in formate generation with a maximum Faradaic efficiency of 92% and a partial current density of 321 mA cm‐2. Ex‐situ structural elucidations reveal the presence of abundant grain boundaries and high retention of S‐S bonds from the covellite phase during CO2RR. Furthermore, thermodynamic calculations demonstrate that S‐S bonds can moderate the binding energies with various intermediates, further improving the activity of the formate pathway. This work is significant in modifying a low‐cost catalyst (Cu) with a non‐metallic substance (S) to achieve comparable performance to mainstream catalysts for formate generation in industrial grade.

A brief review of in situ spectroscopic methods and electrochemical sensors as essential evaluation tools for the electrochemical reduction of CO2 (ElRC)

“…50 Spectroscopies offer a comprehensive understanding of the characteristics of the active sites and reaction mechanisms by examining catalytic systems under the reaction conditions. 119,120 The ElRC reaction was carried out utilizing a potentiostat and the chronoamperometry technique. Both the anode (Pt and Co) and cathode (Sn, Cu, Zn, etc. )…”

Selective CO2 electroreduction to formate over a Cu-based catalyst in S2−-containing electrolyte

“…19–22 In contrast, sulfur doping into Cu-based catalysts has been proven to change the CO 2 RR pathway for selective formate production. 23–27 In a previous work, we developed S-doped Cu 2 O catalysts for CO 2 electroreduction to formate and have proven that a dynamic equilibrium of S exists at the Cu 2 O-electrolyte interface. 28 Besides, S adsorbed on the Cu surface can promote the formation of the *OCHO intermediate of the CO 2 -to-formate pathway.…”