Novel catalyst design for multiphase reactions

The role of catalyst design and its integration with reactor design in multiphase reactions are examined according to the 9 three main levels (nano-, micro- and macro-scale) at which catalyst design should be considered. The main concepts discussed are (i) control of the local effective concentration of reagents and possible deactivating molecules around the active sites by incorporating them into nanoporous cavities and by tuning the hydrophilic character of the support, (ii) possibilities offered by microstructuring catalyst composition (multilayer design and microassembled catalyst bodies) and (iii) opportunities offered by the use of macrostructured catalysts (monoliths, cloths and membranes). The various levels of design are not independent. They must be considered in an integrated view and in close relationship with reactor design. (C) 2003 Elsevier Science B.V. All rights reserved.