Copper electrocatalyst modified with pyridinium-based ionic liquids for the efficient synthesis of ethylene through electrocatalytic CO2 reduction reaction

Reducing carbon dioxide (CO2) emissions from industrial production and improving carbon capture and utilization have emerged as focal points in engineering disciplines. This study focuses on electrochemical catalysis for converting CO2 into valuable raw materials, with the aim of enhancing the selectivity and productivity of high value-added multi-carbon (C2+) products. To address limitations associated with copper cathodes such as low selectivity for ethylene (C2H4) product, low catalytic activity, and high energy consumption during CO2 reduction reaction (CO2RR), pyridinium-based ionic liquids (PyILs) are employed as modifiers for the cathode material. Flow cell is utilized to conduct CO2RR experiment and evaluate the catalytic properties of gas diffusion electrode (GDE) loaded with PyILs modified Cu-based materials (Cu@PyILs). The results suggest that the incorporation of PyILs layers enhances conductivity and facilitates high current density in flow cell. At a cathodic potential of -1.15 V (vs. RHE), Cu@[BPy]Br-2.4 exhibits the highest Faradaic efficiency for C2H4 (FEC2H4 = 31.88 %) and achieves a high current density of 275 mA & sdot;cm- 2. Additionally, Cu@[BPy]BF4-2.4 and Cu@[BPy] PF6-2.4 exhibit FEC2H4 values surpassing 25 %. Meanwhile, the hydrogen evolution reaction (HER) in the flow cell is effectively suppressed, resulting in a FEH2 below 40 %. The present study highlights the exceptional catalytic activity of Cu@PyILs in CO2RR, demonstrating an enhanced selectivity towards C2H4 production. The findings suggest that PyILs have great potential as electrode modifiers.