In this case, however, the reaction orders of m HOR = 0.69 and m HER = 0.20 obtained around equilibrium are drastically different from the ones determined at larger overpotentials. Results for α a + α c = 1 would thus imply a constant Tafel slope, but a change in reaction orders moving from small to larger overpotentials. It is important to note that these fractional val-ues of m HOR and m HER violate the first-order assumption underlying the KL mass-transport correction. It is therefore necessary to evaluate the impact of fractional reaction orders on the mass-transport correction employed.