A study of hydrogen peroxide decomposition in ammonia-peroxide mixtures (APM)

摘要

The stability of ammonia-peroxide mixtures (APM) has been investigated as a function of temperature (24-65 ℃), dilution ratio (1:1:5-1:2:100) and Fe~(2+) concentration (0-10 ppb) using an optical concentration monitor. The results show that the change in hydrogen peroxide concentration increased with an increase in temperature and Fe2~+ concentration in a four hour period. The decomposition rate of hydrogen peroxide increased with an increase in solution pH in the range of 8.0 to 9.7. The kinetic analysis of experimental data showed that the H_2O_2 decomposition reaction follows a first order kinetics with respect to both H_2O_2 and OH~- concentrations. In the presence of Fe2~+, hydrogen peroxide decomposition followed a first order reaction kinetics with respect to H_2O_2 concentration. The calculated rate constant increased with an increase in temperature and Fe2~+ concentration. The apparent activation energy of H_2O_2 decomposition was calculated to be 65 ± 3 kJ/mol. In the presence of Fe~(2+), the activation energy was calculated to be 50 ± 5 kj/mol.