Hydrogen peroxide, as an oxygen

American Petroleum Institute, 1987, Field Study of Enhanced Subsurface Biodegradation of Hydrocarbons Using Hydrogen Peroxide as an Oxygen Source. American Petroleum Institute, Publication No. 4448, Washington, D.C., 76 pp. 

Zappi, M. White, K. Hwang, H.M. Bajpai, R. Qasim. The fate of hydrogen peroxide as an oxygen source for bioremediation activities within saturated aquifer systems. J. Air. Waste Manag. Assoc. 2000, 50, 1818-1830. 

Field Study of Enhanced Subsurface Biodegradation of Hydrocarbons Using Hydrogen Peroxide as an Oxygen Source... 

Scheme 11.57. A representation of the formation of pterosin that snggests that a four-membered ring forms, and it is subseqnently opened to form the hydroxyethyl side chain. The timing of the loss of the methyl group is uncertain, and the retroaldol is without proof. The nature of the oxidizing agents is not known, and the use of hydrogen peroxide as an oxygen donor is unlikely.

We focus here on the use of oxygenases, particularly the blue copper oxygenases, such as laccase and bilirubin oxidase, which can biocatalytically reduce oxygen directly to water at relatively high reduction potentials under mild conditions. First, however, we will briefly consider reports on the use of hydrogen peroxide as an oxidant in biocatalytic fuel cells. 

The use of hydrogen peroxide as an oxidant is not compatible with the operation of a biocatalytic fuel cell in vivo, because of low levels of peroxide available, and the toxicity associated with this reactive oxygen species. In addition peroxide reduction cannot be used in a membraneless system as it could well be oxidized at the anode. Nevertheless, some elegant approaches to biocatalytic fuel cell electrode configuration have been demonstrated using peroxidases as the biocatalyst and will be briefly reviewed here. 

There are two mechanisms that are considered in the oxygen reduction reaction. In the series mechanism oxygen molecules are protonated twice generating hydrogen peroxide as an intermediate which can then be further reduced. In the direct... 

In contrast to such classical processes, the catalytic epoxidation with hydrogen peroxide as an oxidant offers advantages because (1) it generates only water as a by-product and (2) it has a high content of active oxygen species [3-6]. 

It s oxygen gas that produces the foam when you use hydrogen peroxide as an antiseptic to clean a cut or scrape. It s also oxygen that bleaches hair when a peroxide bleach is used. Some household cleansers use oxygen bleach rather than chlorine bleach. 

Nowadays, it has been demonstrated that the reaction is indeed structure sensitive with a multielectron transfer process that involves several steps and the possible existence of several adsorption intermediates [93-96]. The main advantage that we have with the new procedures with respect to cleanliness is that we have well-ordered surfaces to study a complex mechanism such as the oxygen electroreduction reaction [96-99]. In aqueous solutions, the four-electron oxygen reduction appears to occur by two overall pathways a direct four-electron reduction and a peroxide pathway. The latter pathway involves hydrogen peroxide as an intermediate and can undergo either further reduction or decomposition in acid solutions to yield water as the final product. This type of generic model of a reaction has been extensively studied since the early 1960s by different authors [100-108]. 

In a second reaction, the activated hydrogen (taken up from the catalyst) is oxidized with molecular oxygen. According to Macrae, this second step proceeds through hydrogen peroxide (as an intermediate), the existence of which was demonstrated by the formation of cerium peroxide when the reaction was carried out in the presence of cerium (III) hydroxide. The hydrogen peroxide produced is rapidly decomposed by the catalyst. 

Schematic representation of the electrochemical reactions of oxygen reduction with formation of hydrogen peroxide as an intermediate product.

Figure 1 shows electrochemical oxygen reduction mechanism in alkaline system. Oxygen reduction in alkaline system is cmisidered to proceed by two overall pathways. One is the direct 4-electron pathway (O2 + 4e + 2H2O = 40H ), and the other one is the peroxide pathway (O2 + 2e + H2O = H02 + OH ), which produces hydrogen peroxide as an intermediate product. The H02 is further reduced to OH by either electrochemical reaction or catalytical decomposition reaction. The reactions are dependent on the kind of electrocatalysts [4]. 

---