To investigate whether this conclusion holds for different Ag thickness, Figs. ) and 5(d) show the results for the Ag500 and Ag500P36 electrodes, respectively. As in the 200 nm case, one sees that the plasma-treated electrode has significantly higher current density, markedly higher stability of the FECO, with only a minor decrease after 24 hours in stream, and increased CO selectivity, with only a couple of percent FEH2.