Catalytic palladium membrane hydrogenation effect

Effect of a Model Hydrogenation on a Catalytic Palladium Membrane... 

Dittmeyer et al. [9] reviewed the applications of a palladium membrane reactor to catalytic dehydrogenation of paraffins. Based on simplified simulation, it was concluded that a beneficial effect of hydrogen removal through the membrane could be offset by strong adsorption of the product olefin on the catalyst surface that would eliminate the active surface sites and effectively slow down the forward reaction rates. Also, it was observed that the long time stability and reactivity of the palladium membranes would require more research. 

Itoh, N., Xu, W. C., Hara, S., Kakehida, K., Kaneko, Y., Igarashi, A. (2003). Effects of hydrogen removal on the catalytic reforming of n-hexane in a palladium membrane reactor. Industrial and Engineering Chemistry Research, 42, 6576. 

The key problem of the cross-flow reactor is not how to construct an effective separation of the two flowing phases. It is instead connected with how to design the porosity and location of the catalytic active zones of the separating walls so that the transport resistance across the wall does not limit the conversion and the selectivity of the chemical reactions. Palladium-alloy membranes, or thin films of these alloys on porous ceramic tubs, seem to have the potential to be good solutions of the separating-wall problem for cross-flow reactors used for hydrogenation reactions. 

A novel catalyst consisting of colloidal palladium adsorbed onto the surface of a water-insoluble polymer, polyvinylpyrrolidone, has been shown to hydrogenate only the outer leaflet of rat platelets [59]. The effect of hydrogenation was to influence the asymmetric distribution of the phospholipids of the membrane. Catalytic hydrogenation of a phytopathogenic fungus [60] has also been reported. 

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