The SERS analysis provides direct evidence for the alkalinity developed under CO2 electrolysis, where the local pH f or the pure Cu f oam and the CO-selective bimetallic foams rises from 7-8 to 10-11 during the first 10 minutes of CO2 electrolysis. Operando SERS of the CO-selective bimetallic f oams showed strong peaks f or the CO intermediates, besides both of the CO-selective foams showed higher CO surf ace coverage compared to the pure Cu f oams. On the other hand, the HCOO --selective bimetallic catalysts showed only peaks related to the f ormate-pathway (no peaks f or CO-pathway were detected) which agree well with the observed CO2ER perf ormance.