Silver over supported catalysts, particle size

As in the case of normal supported catalysts, we tried with this inverse supported catalyst system to switch over from the thin-layer catalyst structure to the more conventional powder mixture with a grain size smaller than the boundary layer thickness. The reactant in these studies (27) was methanol and the reaction its decomposition or oxidation the catalyst was zinc oxide and the support silver. The particle size of the catalyst was 3 x 10-3 cm hence, not the entire particle in contact with silver can be considered as part of the boundary layer. However, a part of the catalyst particle surface will be close to the zone of contact with the metal. Table VI gives the activation energies and the start temperatures for both methanol reactions, irrespective of the exact composition of the products. 

Fig. 21. Turnover frequency TOF and selectivity (fraction of ethylene reacted that forms ethylene oxide) for the partial oxidation of ethylene over supported silver catalysts, presented as a function of fraction exposed FE and mean particle size d (see Table XIV for details of the studies).

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