The chronoampermetry was used to measure the Fe3+ diffusion coefficient of 0.031 16 mol/kg of FeCl3 in the ionic liquid, BPBF4, at GC working electrode referred to Al/Al3+ and at different scan rates over the temperature range from 293.15 to 343.15 K. Since the Fe3+ reduction reaction is a reversible process with one transfer electron, according to Cottrell′s equation, the values of diffusion coefficient of Fe3+ at different temperatures were estimated. As temperature increases, the values of the diffusion coefficient also increase owing to the diminution of the BPBF4 viscosity. The values of diffusion coefficient were fitted with the method of least-square according to Arrenius′ equation, and value of diffusion activation energy of Fe3+, ED=49.5 kJ/mol, was obtained from Arrenius′ slope.
