Stabilization of H2O2 in the presence of Fe(II) and Mn(II) impurities under alkaline conditions

Stabilization of aqueous H2O2 solutions containing small amounts of transition metal impurities [e.g., Mn(II) and Fe(II)] was studied in terms of UV/Vis and electron spin resonance spectroscopy and oxygen concentration measurements at pH similar to 11. The results show that aspartic acid diethoxy succinate (AES) could stabilize H2O2 Solution when Mn(II) and Fe(II) were present. Diethylenetriamine pentaacetic acid (DTPA) showed similar behavior, but was not able to stabilize the solutions as efficiently as AES. In the long-term regime, Na-poly-alpha-hydroxyacrylate was almost as effective a stabilizing agent as AES. Na-acrylate-3-allyloxide-2-hydroxy propane Na-sulfonate copolymer (Aqualic) could decrease H2O2 decomposition by one order of magnitude, but it was the least efficient stabilizing agent among the substances studied. Furthermore, generation of superoxide radical was not suppressed in the presence of Aqualic.