Kinetics of Iron‐catalyzed decomposition of hydrogen peroxide in alkaline solution

Abstract

The decomposition of alkaline hydrogen peroxide solutions at 20°C has been studied in the presence of both supported iron catalysts and in systems with iron initially in solution. Studies with an iron-alumina supported catalyst showed the decomposition reaction was first order with respect to total peroxide concentration, while studies with alkaline Fe3' produced more complex behavior. This has been attributed to the presence of at least two distinct catalytically active iron species. The first species is highly active and gives rise to high initial rates of reaction. A decrease in concentration of this species is observed together with an increase in concentration of a second, less active, iron species. The catalytic behavior of this "aged iron species was found to be very similar to that of the supported iron catalyst.

Radiolytic modelling of spent fuel oxidative dissolution mechanism. Calibration against UO2 dynamic leaching experiments

“…However, most of the authors agree that hydrogen peroxide oxidation occurs by radical formation with very high oxidation potentials, and with the radical hydroxyl ( Å OH) as one of the main species generated in this process [15][16][17]. In addition, H 2 O 2 auto-decomposition is also known to be catalysed on oxide surfaces containing mixed oxidation states [18]. When hydrogen peroxide concentration ranges 10 À4 M < [H 2 O 2 ] < 10 À2 M, the oxidative dissolution and hydrogen peroxide decomposition should occur simultaneously [12].…”

Kinetics of hydrogen peroxide decomposition with complexed and ?free? iron catalysts

“…For example, Fe(III), as ferrihydrite (the most soluble amorphous form), is soluble up to 10 Ϫ3 M at pH 3.0 and 10 Ϫ8 M at pH 8.0, as calculated using MINTEQ [25]. The reactions using Fe(III) are first order with respect to hydrogen peroxide concen- tration and the rate constants have been determined [9,26]. Figure 3 shows the effect of pH on the initial decomposition rates of hydrogen peroxide.…”

Reactivity of hydrogen peroxide towards Fe3O4, Fe2CoO4 and Fe2NiO4

“…Kim bases his work on a detailed analysis of the surface oxidation of stainless steel immersed in aqueous solutions containing the above redox agents [10,11]. These studies provide some insights into the relative effects of H 2 [12][13][14][15][16][17][18]. A detailed analysis of the decomposition of H 2 O 2 on goethite (a-FeOOH) can be found in the work by Lin and Gurol [19].…”