Fig. Fractional deviation from equilibrium for reactions (6), ( ) and (8) in the simulation domain. The data shown is for a total current density of 1 mA/cm 2 , a CO Faradaic efficiency of 0.8 and a potential of -0.32 V vs PZC at the OHP. We have removed the deviation values for the initial 1 nm from the OHP since the formation of the EDL wildly distorts the species concentrations.