Table ). Moreover, the value of γ = 0.53 obtained from the Butler-Volmer fits reasonably agrees with the value determined from micropolarization analysis (γ = 0.65). It is interesting to note that on the overpotential scale, both fits for α a + α c = 1 and α a + α c = 2 yield the same result of γ = 0.53. However, after conversion to the fixed potential scale, very different reaction orders (m HOR and m HER ) are found for the Butler-Volmer models with α a + α c = 1 and α a + α c = 2. This demonstrates that reaction orders determined on an overpotential scale must first be transformed to a fixed potential scale before assessing the validity of a certain KL mass-transport correction. In particular, even an apparent fractional reaction order of 0.5 on the overpotential scale can transform to integer reaction orders of one and zero on a fixed potential scale, as shown by the results for α a + α c = 2 in Table .