Electrochemical study of carbon dioxide reduction at copper–palladium nanoparticles: Influence of the bimetallic composition in the CO poisoning tolerance

•CO2RR is studied at Pd100–xCux nanopowders in the form of solid solution alloys.•Focus is set on the acquisition and interpretation of electrochemical signals.•The synergy between Pd and Cu is evidenced directly by cyclic voltammetry.•The critical time for full poisoning exhibits a volcano dependence on composition.•Pd70Cu30 is identified as a close to optimal composition in terms of CO tolerance.