Reaction Planner

Figure 19 CO + NO reaction Arrhenius plots for single-crystal, model planner-supported, and Pd/Al203 powder catalysts. The powder catalyst data were taken in the flow reaction mode (4.4/5.2 CO/NO ratio, steady state), and the model catalyst and single-crystal data were acquired for a batch reaction mode in 1 Torr of each reactant. (From Ref. 32.)...

In the above sections, we have presented the electrode kinetics of electron-transfer reaction and reactant transport on planar electrode. However, for practical application, the electrode is normally the porous electrode matrix layer rather thtin a planner electrode siuface because of the inherent advantage of large interfacial area per unit volume. For example, the fuel cell catalyst layers are composed of conductive carbon particles on which the catalyst particles with several nanometers of diameter are attached. On the catalyst particles, some proton or hydroxide ion-conductive ionomer are attached to form a solid electrolyte, which is uniformly distributed within the whole matrix layer. Due to the electrode layer being immersed into the electrolyte solution, this kind of electrode layer is called the flooded electrode layer . 

However, if the electron transfer kinetics of oxidant reduction in Reaction (5-1) is much slower than that of diffusion— convection process, the oxidant s surface concentration cannot be exhausted to zero unless a very larger overpotential is controlled. In this case, the obtained Levich plot of 7dc,o vs according to Eqn (5.14a) is not a straight line anymore, and it will gradually fall off with increasing as shown in Figure 5.5(B). In this case, for a planner smooth disk electrode, we can use the equation similar to Eqn (2.69) to take care of the effect of a slow electron-transfer kinetics ... 

One of the most elegant methods for the selective formation of C—O bonds is the catalytic Jacobsen-Katsuki epoxidation, the enantioselective synthesis of optically active epoxides by oxygen-transfer reactions with chiral, nonracemic manganese 0x0 salen complexes. These complexes have been suggested as the catalytically active species in epoxidations catalyzed by metal-salen and porphyrin complexes [78]. One of these complexes was for the first time isolated and characterized by Feichtinger and Planner through ESI-MS studies [79]. 

Square-planner 16-electron complexes are coordinatively unsaturated and are usually employed to catalyse the reactions of organic molecules. Catalytic systems involving ML4 complexes of Pd (II), Pt (II) and Rh (I), like hydrogenation catalyst [RhCl(PPh3)3], are well known. 

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