Kinetic study of the catalytic decomposition of H2O2 in phosphoric acid medium

• The decomposition of hydrogen peroxide by the ferrous ion in phosphoric medium follows pseudo first order kinetics.
• The decomposition rate of hydrogen peroxide is accelerated by increasing Fe2+ concentrations and temperature.
• The decomposition rate is favored by increasing P2O5 concentrations.
• Ferrous ions lower the energy barrier of hydrogen peroxide decomposition.

The kinetics of hydrogen peroxide decomposition in phosphoric acid media containing ferrous ion was investigated. The results indicated that this reaction followed the pseudo-first-order kinetic model. The decomposition rate of H2O2 was accelerated by increasing Fe2+ concentrations and temperature. However, higher levels of H2O2 inhibited the reaction kinetics. Based on the rate constants obtained at different temperatures, the empirical Arrhenius expression of H2O2 decomposition was derived. The derived activation energy for H2O2 decomposition by ferrous ions is 57.1 kJ/mol.