Electrochemical Study on Decomposition of Hydrogen Peroxide with Fe(II)

Decomposition of H₂O₂ with Fe²⁺ was studied with SnO₂ electrodes. By chronoamperometric and voltammetric techniques, the diffusion coefficients of Fe^3* and H ₂O₂ were estimated to be 5 × 10‐₆ and 2 × 10⁻⁵ cm²/s, respectively; the rate of decomposition of H₂O₂ with Fe²⁺ was proportional to [H₂O₂]^1/2·[Fe²⁺]² at a smaller concentration of Fe²⁺, but to [H₂O₂]^1/2·[Fe²⁺] when [Fe²⁺] was increased, indicating the formation of ferryl ion and the electron exchange between it and Fe²⁺ playing important roles. This catalytic decomposition. was dependent on pH; the maximum rate was observed to occur about pH = 1.5.