The presence of adsorbed *CO on the surface of pure Cu and CO-selective bimetallic (Cu85In15 and Cu85Sn15) f oams is evidenced by the presence of Raman peaks at ~280-284 cm -1 , 350-360 cm -1 and 1970-2070 cm -1 , assigned to the frustrated CO rotational mode (P1), Cu-CO stretching (P2) and intramolecular C≡O stretching, respectively (Figure ). P2 and P1 Raman bands usually indicate the interaction between the CO-intermediate and Cu surf ace. The intensity ratio of P2 and P1 Raman peaks (P2/P1) can be used to assess the *CO surface coverage at the solid-liquid interface during CO2 electrolysis, with the ratio and *CO coverage scaling together. As seen in Figure , CO-selective bimetallic f oams (Cu85In15 and Cu85Sn15) exhibited a higher P2/P1 ratio compared to the pure Cu f oam (Fig. ), suggesting a higher *CO surface concentration at the bimetallic foams compared to the pure Cu f oam, which correlates with higher FEs for CO evolution. On the other hand, neither of the CO-adsorption related peaks were observed f or the HCOO --selective bimetallic foams (Cu25In75 and Cu40Sn60), which is expected since they are mainly HCOO -producers (Figure ). Additionally, both exhibited a strong broad peak between at 2840-2950 cm -1 assigned for the C-H stretching (mainly HCOO -) together with a well resolved peak at ~1595-1600 cm -1 attributed to the C-O stretching of the HCOO --pathway carboxylate intermediate (O-bound).