Nafion membranes reaction

Jiang J, Kucernak A. 2004. Investigations of fuel cell reactions at the composite microelectrode solid polymer electrol3de interface. I. Hydrogen oxidation at the nanostructured Pt Nafion membrane interface. J Electroanal Chem 567 123-137. 

Another example for microreactor-controlled selectivity in the reaction of olefin with x02 can be found in the photosensitized oxidation of DPB in ZSM zeolite [160], Nafion membranes [161], and vesicles [163], In homogeneous solution, ZSM zeolite, and Nafion membranes, the oxidation of DPB with 02 yielded the [2 + 4] reaction product, endoperoxide 6, as the unique product (Figs. 15 and 18). In sharp contrast, in vesicle medium, the oxidation produced the aldehydes 1 and 2 ([2 + 2] reaction) in quantitative yield as described in Section III.B.l (Fig. 

Pt/XC-72R catalyst mixture that was sprayed directly onto one of the graphite separator plates that came with the high-flow rate single-cell electrolysis cell. We have found that the copper(I) oxidation reaction does not require a catalyst (see below). Thus, a catalyst-free graphite separator plate was used as the anode. Nafion membranes were used as the electrolyte for H+ conduction. 

The theoretical cell voltage of a DMFC at standard conditions is 1.20 V. The materials used in DMFCs are similar to those in PEMFCs. Pt, PtRu, and Nafion membrane are used as cathode catalyst, anode catalyst, and proton transfer membranes, respectively. However, the catalyst loading in a DMFC is much higher than the loading used in H2/air fuel cells, because both side reactions are slow (Pt loadings 4 mg/cm2 for a DMFC, 0.8 mg/cm2 for a H2/air fuel cell). 

Addition of sulphur trioxide is an important step in the process for the production of Nafion membrane (see Chapter 8, Section llA) [173] reaction with chlorotrifluoro-ethene (CTFE) is not regioselective [174] (Figure 7.53). 

Fig. 11. Reactions of dinuclear ruthenium complex at Nafion membrane coated on ITO electrode at different pH conditions (ITO/Nf/Ru-dimer)...

Nation film during the catalytic water oxidation. The absorption spectra did not show any further changes in repeated cyclic scans. When an applied potential of 1.2 V (vs. SCE) was applied, Ru-brown underwent oxidation to produce Ru -Ru -Ru complex and this Ru -Ru -Ru complex is reduced by water molecules to produce Ru-brown (Ru -Ru" -Ru ) by four-electron process. Independent of pH condition, the cyclic reaction between Ru -Ru" -Ru and Ru Ru -Ru showed only the spectrum of Ru-brown The reactions involved at Nafion membrane is summarized in Fig. 14. This report clearly shows that in the cyclic catalysed water oxidation reaction the Ru-red and Ru-brown complexes combined in a Nafion membranes act as four-electron catalyst, independently of pH, and the complex is stabilized against decomposition in the membrane. 

Fig. 5. Reaction-order plots for the ORR process at the Pt/Nafion membrane interface. A unity reaction order is evaluated from the dependence of the apparent Jo on oxygen partial pressure [5], (Reprinted by permission of the Electrochemical Society).

Photoinduced charge separation processes in the supramolecular triad systems D -A-A, D -A -A and D -A-A have been investigated using three potential energy surfaces and two reaction coordinates by the stochastic Liouville equation to describe their time evolution. A comparison has l n made between the predictions of this model and results involving charge separation obtained experimentally from bacterial photosynthetic reaction centres. Nitrite anion has been photoreduced to ammonia in aqueous media using [Ni(teta)] " and [Ru(bpy)3] adsorbed on a Nafion membrane. 

Barnes et al. (112) considered the use of suifonate-ionomers, SPS and perfluorosulfonate membranes, as catalysts for carrying out chemical reactions. In a variation on this theme, Maurltz et al. have prepared unique mlcrocomposlte membranes by the In situ growth of silicon oxide in solvent swollen Nafion membranes. This work is described later in this book. 

The objective of this work was to affect the ia situ growth of silicon oxide microclusters or interpenetrating networks in Nafion membranes via the sol-gel reaction for tetraethoxysilane (TEOS). The underlying hypotheses are ... 

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