Similar to H2 evolution, methane formation on Cu has been shown to be suppressed by increased local pH on oxide-derived samples. If locally alkaline (pH>12) conditions are indeed unavoidable with the currently-used electrolytes, then these results suggest that an alternate reaction mechanism or catalyst may be needed to realize selective methane formation at elevated current densities. An interesting fundamental result would then be the demonstration of a catalyst capable of selective methane formation under alkaline or locally alkaline conditions. Inversely, for multi-carbon product formation on Cu, higher local pH conditions have been experimentally demonstrated to be an important factor for promoting carbon-carbon coupling. The higher observed activity toward multi-carbon species at lower potentials could be due to the imporved CO onset potentials, changes to the binding energy of *CO, a direct effect of the local conditions on the energetics of the coupling step itself, or a cumulative effect of multiple factors. There does not appear to be any strong correlations between pH and product distribution after C-C coupling, however, as most studies report similar alkane to alkene ratios as in lower current density H-cell experiments.