Mechanisms redox reactions

Although the redox reaction mechanisms of iridium oxide are still not clear, most researchers believe that the proton exchange associated with oxidation states of metal oxides is one of the possible pH sensing mechanisms [41, 87, 100, 105], During electrochemical reactions, oxidation state changes in the hydrated iridium oxide layer are... 

Kano K, Uno B (1993) Surface-redox reaction mechanism of quinones adsorbed on basal-plane pyrolytic graphite electrodes. Anal Chem 58 2009-2012. 

If, in indirect electrolyses, the homogeneous reaction step is a chemical step combined with a redox reaction (mechanism B), some more advantages are obtained ... 

Solvent Effects on Redox Potentials and Redox Reaction Mechanisms... 

The characteristics of redox reactions in non-aqueous solutions were discussed in Chapter 4. Potentiometry is a powerful tool for studying redox reactions, although polarography and voltammetry are more popular. The indicator electrode is a platinum wire or other inert electrode. We can accurately determine the standard potential of a redox couple by measuring the electrode potential in the solution containing both the reduced and the oxidized forms of known concentrations. Poten-tiometric redox titrations are also useful to elucidate redox reaction mechanisms and to obtain standard redox potentials. In some solvents, the measurable potential range is much wider than in aqueous solutions and various redox reactions that are impossible in aqueous solutions are possible. 

DeNOx reaction involves a strongly adsorbed NH3 species and a gaseous or weakly adsorbed NO species, but differ in their identification of the nature of the adsorbed reactive ammonia (protonated ammonia vs. molecularly coordinated ammonia), of the active sites (Br0nsted vs. Lewis sites) and of the associated reaction intermediates [16,17]. Concerning the mechanism of SO2 oxidation over DeNOxing catalysts, few systematic studies have been reported up to now. Svachula et al. [18] have proposed a redox reaction mechanism based on the assumption of surface vanadyl sulfates as the active sites, in line with the consolidated picture of active sites in commercial sulfuric acid catalysts [19]. Such a mechanism can explain the observed effects of operating conditions, feed composition, and catalyst design parameters on the SO2 SO3 reaction over metal-oxide-based SCR catalysts. 

Activated complex, bridged, redox reaction mechanisms and, 19-32 outer-sphere, redox reaction mechanisms and, 12-19... 

The PR studies on XO and XDH provide qualitatively similar sequences of internal ET reactions and illustrate the usefulness of this method in delineating enzymatic redox reaction mechanisms (167-169, 172). No one to date has attempted to obtain more quantitative information regarding the ET reactivity of the individual sites. Better characterization of the individual ET steps in XO will surely be required for this purpose. 

In our previous publication [6], we have reported for the first time on the photocatalytic reduction of NO by carbon monoxide over a Mo03/Si02 catalyst (2.5 wt % of Mo). The reduction proceeds under UV-irradiation (X < 360 nm) at ambient temperature, N2, N2O, and CO2 being the reaction products. A redox reaction mechanism was proposed in [6] consisting of two st es (a) photoinduced reduction of the initial surface Mo to Mo by CO and b) dark oxidation of Mo by NO to yield N2O and N2 and to restore Mo. Both stages can be accomplished separately or combined in one photocatalytic process. A Mo-nitrosyl paramagnetic complex was suggested to be an intermediate in the photocatalytic NO reduction by CO. 

In conclusion, it appears that the proposed redox reaction mechanism agrees well the kinetic and EPR data obtained in this work. The results of a kinetic study of N2O + CO - N2 + CO2 photocatalytic reaction over Mo03/Si02 as well as those of photoliuninescence experiments in the presence of different quenchers will be reported in forthcoming publications. 

The authors advocated a redox reaction mechanism (Scheme 1.82), whereby 304 reacts with ArCH2Y to produce the solvent cage radical pair 306, which collapses to 307. Elimination of methanol from 307 yielded 308. Here, the loss of HY was believed to occur homolytically to yield 305. ... 

With this short expose into the early works, we have shown the scattering in approaches even initially to cover most of the possible types of strategies, methods, and models. With this in mind, we move on to the modem works with a maintained scatter in approaches, but adding also new dimensions in targets and aims for the predictive calcnlations - most notable are the work on redox reaction mechanisms and the trend to introdnee more complex solvent surroundings. 

Fig. 1 Typical redox reaction mechanism for an organic cathode material with a caibonyl redox center...

The academic interest in mixed oxides and catalysts between 1930 and 1950 clearly promoted the understanding and development of oxidation catalysts. Many improved formulations had, of cotrrse, been gradirally developed by largely empirical methods for organic oxidation processes from the 1940s, and these led to the redox reaction mechanism proposed by Mars and van Krevelen in 1954. ... 

Figure 4.1 WGS redox reaction mechanism (left) and structures (right).

---