ELECTROCHEMICAL STUDY ON DECOMPOSITION OF HYDROGEN-PEROXIDE WITH FE(II)

Decomposition of H2O2 with Fe2+ was studied with SnO2 electrodes. By c hronoamperometric and voltammetric techniques, the diffusion coefficie nts of Fe3+ and H2O2 were estimated to be 5 x 10(-6) and 2 x 10(-5) cm (2)/s, respectively; the rate of decomposition of H2O2 with Fe2+ was p roportional to [H2O2](1/2).[Fe2+](2) at a smaller concentration of Fe2 (+), but to [H2O2](1/2).[Fe2+] when [Fe2+] was increased, indicating t he formation of ferryl ion and the electron exchange between it and Fe 2+ playing important roles. This catalytic decomposi tion was dependen t on pH; the maximum rate was observed to occur about pH = 1.5.