decreases significantly with current, while 𝑅 𝑐𝑡,1 remains essentially constant until 𝐼 > 𝐼 0,1 . When the difference between I0,1 and I0,2 is large, a "plateau" in the resistance versus current plots can emerge in the current range between I0,1 and I0,2. Because 𝑅 𝑐𝑡 ′ decreases more quickly with current than Rct, the differential charge-transfer resistance provides a more pronounced separation between the resistance versus current features for each reaction step. Comparing the normalized Rct and 𝑅 𝑐𝑡 ′ versus current curves for a two-step reaction with relatively small differences between I0,1 and I0,2, it is evident that differential resistance measurements can resolve much larger changes in the magnitude of resistance, and in the shape of the resistance versus current curve (Fig. ). In summary, at either very low or very high current densities, or when 𝐼 0,1 = 𝐼 0,2 , a two-step reaction will be indistinguishable from a one-step reaction, but the apparent α value can still indicate the possibility of a two-step reaction. Additionally, differential-charge transfer resistance measurements at intermediate current densities appear to be a suitable tool for directly deconvoluting the resistance contributions of multiple reaction steps in series, even when the exchange currents are similar.