H2O2, catalytic decomposition

The second pathway is seen distinctly at mercury and graphite electrodes. These electrodes are quite inactive in the catalytic decomposition of H2O2. Moreover, at them the potential where the peroxide is reduced further is more negative than the potential where it is formed from oxygen. Hence, within a certain range of not too negative potentials, the reaction can occur in such a way that the hydrogen peroxide formed accumulates in the solution. 

The true peroxoborate has been reported to detonate on light friction [ 1 ]. The common tetrahydrate is not a peroxoborate, but NaBO2.H2O2.3H2O, and while subject to catalytic decomposition by heavy metals and their salts, or easily oxidisable foreign matter, it is relatively stable under mild grinding with other substances [2],... 

Attempts were therefore made to catalytically destroy H 0 by incorporating a small packed bed reactor immediately after the D.S. ana before the introduction of SOD. We have previously used microsized reactors packed with granular MnO (18.21.231 for the catalytic decomposition of H2O2. Experiments in the flow injection mode showed that using a large amount of MnO (ca. 25 mg) in the reactor resulted in not only decomposition of H 02 but also the oxidation of more than half of the collected S(IV). Reducing the... 

Studies on reactions between different oxidants and FejO, Fe2Co04 and Fe2Ni04 reveal similar trends in reactivity for the oxidants. An important exception is observed for H2O2 where the reactivity is markedly lower than expected from the trend for the other oxidants.The rationale for this is probably that H2O2 is consumed by catalytic decomposition (as will be discussed below) on the surface while the other (stronger) oxidants are capable of oxidizing the metal oxides used in this study. 

The easy regeneration of V - and Cr -peroxo species from the reaction of 0x0 species with hydrogen peroxide enables the catalytic oxidation of the hydrocarbon to occur. However, the synthetic usefulness of these reactions is limited by the parallel catalytic decomposition of H2O2 associated with the decomposition of the peroxo species, and by the consecutive oxidation of the... 

Although the effect is not large, filtration time is shorter and the plutonium concentration in the filtrate is lower if metallic impurities are present. From a practical standpoint this means, simply, that some impurities can be present in the plutonium feed solution. Since different impurities can have different effects on the catalytic decomposition of H2O2, the... 

Another line of catalytic work was started by Thenard (1818). He discovered hydrogen peroxide cind he who discovers H2O2 is apt also to discover its catalytic decomposition. Thenard did, and he investigated the matter carefully using both homogeneous and heterogeneous catalysts. 

These results may be compared with those reported by Rizkalla et al. (1986) wherein the reaction between H2O2 and ethylenediaminetetraacetato-Ce(IV) was studied. These authors report that, while there was catalytic decomposition of the H2O2, there was no evidence for decomposition of the ligand. They determined two second-order rate parameters (0.054 and 0.171 which are attributed to the decomposition... 

A useful nitrogen-free sequestrant for H2O2 and peracids is HEDP (1-hydroxyethylidene diphosphonic acid). In general, solutions containing both peracids and free hydrogen peroxide are more prone to catalytic decomposition than either component alone [60], since the two peroxides themselves represent a redox couple. 

Stable to oxidation by many media, and do not undergo autoxidation. H2O2 cleaves the bonds only slowly. (V) and bis(3-methylborolane) do not react with CH2N2 at room temperature the failure to observe the catalytic decomposition to N2 and polymethylene indicates that the borolane boron is exclusively four-coordinated. Bis(borolanes) also do not catalyze substituent exchange on boron 8, 9, 12) only above 100° C do they act like open-chain alkyldiboranes. 

Scfteme 7. Mechanisms of oxidation of I.Fe" to LFe " and catalytic decomposition of H2O2 by... 

The homogeneous catalytic decomposition of hydrogen peroxide (H2O2) (with Fe ions as catalyst) in a batch reactor can be formally described by a first-order reaction ... 

Figure 4.10.22 (a, b) Evolution of temperature in an adiabatic batch reactor during catalytic decomposition of H2O2, ATj = 58 K To = 302 K data from Baerns eto/. (2006). 

The catalytic decomposition of hydrogen peroxide by living tissue was first observed in 1818 by Th nard (342), the discoverer of H2O2, and the production of oxygen from H2O2 was first ascribed to enzyme action by Schonbein (307) in 1863. 

The residual can be determined gasometricaUy after catalytic decomposition. Elliott (130) used MnO to this end, whereas Agner (19), utilizing several donor substances in the assay, employed catalase for the decomposition of the remaining H2O2. 

Fig. 16. Catalytic decomposition of H2O2 by ferric triethylenetetramine (I). A peroxide ion in the complex reacts with a second peroxide ion by hydride ion transfer so the peroxide in the complex is reduced to 2(OH ) and the second peroxide is oxidized to O2. In (II) the peroxide (0—OH ) ion displaces one hydroxyl ion. In (III) another hydroxyl ion is displaced with the simultaneous chelation of the peroxide in two positions. When another peroxide ion reacts with (III) a hydride ion ( H) is transferred to the complex to form —0 H as in (I) and O2.

The reduction of hydrogen peroxide (reaction 14 or 15) may start with either an electrochemical step [10,55,56] or a chemical step [23, 24,57—59]. Molecular oxygen should be formed if the Haber-Grinberg mechanism [60] of the catalytic decomposition of H2O2 on platinum... 

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