To distinguish between surface redox processes and possible electrocatalytic reactions, we determined the total charge passed in both scan directions for regions with positive and negative current densities. The corresponding values for batches 3 and 4, from Figures and can be found in Table . Considering that one electron is transferred per surface atom and that a reconstructed Au(111) surface consists of 1.4 × 10 15 atoms per cm 2 , one would expect a charge of 222 µC cm -2 . A single molecule from the IL is, however, larger than a Au atom on the surface and hence covers several sites. Consequently, the total charge for monolayer adsorption is lower compared to the case where adsorbates covered every single surface atom. In type I, the total charge passed in regions with negative current density exceeds the charge of 222 µC cm -2 significantly. In the case of type II, the total charge passed is lower compared to that of type I, but still larger than that for a single electron transfer per surface atom. The charges are also higher than that expected for a process involving two electrons, such as the formation of an atomic oxygen layer by water dissociation. Larger charges could indicate bulk or near-surface oxidation, which would lead to significant electrode restructuring during continuous potential cycling. This process is, however, rather unlikely on Au(111) under these conditions. Thus, for both types, an electrocatalytic process is expected to occur concomitantly with the surface redox processes, which will be discussed below.