To predict the trends across different cations and identify the best operating conditions on Ag(111), we varied the buffer to Cs + -based and Li + -based carbonate solutions and compared the results with K + . As Li 2 CO 3 has a solubility limit of 0.18 mol/1L H 2 O at 25°C (KHCO 3 has a solubility limit 3.61 mol/1L H 2 O), we did not consider buffer concentrations with [Li + ] > 0.1 M. range, in agreement with the experimental data . For Li + buffers, the current density is higher (although within an order of magnitude) with respect to K + at less negative potentials; but becomes severely transport limited at intermediate potentials with the maximum reached current densities of the order of 10 -4 mA cm -2 . This is due to the larger hydrated diameter of Li + (d =7.64 Å ) which leads to a steric limit of only 3.72 M at OHP and significant size exclusion effects. The direct comparison with the experimental current densities (Figure ) shows that for Li + , similarly to K + , the peak current density is 2-orders of magnitudes lower than the experimental results. For Cs + , the experimental and predicted peak current densities are of the same order of magnitude.