Figures and show the Cu 2p spectra, where the shift in lower binding energies and the reduced intensity of the satellite peaks after electrolysis indicate the reduction of Cu 2+ to Cu⁰, confirming the transformation of Cu2O to a more metallic Cu state. This change in oxidation state suggests enhanced electronic conductivity and improved CO adsorption on metallic Cu sites, promoting C-C coupling. In Figure , the Sn 3d spectra show minimal shift in binding energy, indicating the stability of Sn species during CO2 reduction. The presence of Sn in the +4-oxidation state before and after electrolysis suggests that Sn acts as an electronic modulator, maintaining a consistent electronic environment that stabilizes CO intermediates, thereby enhancing C2 product selectivity. Figure displays the Cl 2p spectra, where the consistent binding energies before and after electrolysis confirm that chloride ions remain anchored to the catalyst surface, preventing leaching during prolonged CO2 reduction. This stable Cl environment is crucial for suppressing hydrogen evolution (HER) and increasing the local CO concentration, favoring C-C coupling. The C 1s spectra in Figure reveal the presence of C-C/C=C and C-F species of PTFE coated GDL, and C-F species are from PTFE coated GDL. Figure shows the K 2s spectra of the post-CO2 electrolysed CTC-65, confirming the adsorption of K + ions from the KOH electrolyte, which likely contribute to electrostatic stabilisation of CO2 reduction intermediates. The presence of K⁺ ions emphasize the significance of the KOH electrolyte in facilitating CO2 electrolysis using CTC-type halidebased electrocatalysts. These observations collectively demonstrate the synergistic roles of Sn and Cl in stabilising key intermediates and optimising the electronic structure of the CTC catalysts, leading to enhanced selectivity and efficiency for C2 hydrocarbon production. The XPS analysis further confirms the successful incorporation of Cu, Sn, and Cl species into the Cu2O/SnCl4 GDE which is in correspondence with the SEM elemental mapping.