INDUSTRIAL-SCALE OXO SYNTHESIS WITH AN IMMOBILIZED CATALYST

Industrial Oxo Synthesis with Immobilised Catalyst. The use of water-soluble catalysts represents a significant advance in homogeneous catalysis; ''immobilisation'' of the catalyst in a second immiscible liquid phase has the effect of ''heterogenisation'' and allows the advantages of heterogeneous processing (long lifetimes, straightforward technology) to the combined with those of the homogeneous mode (gentle reaction conditions, high activity and selectivity). In particular, the decisive advantage of homogeneous catalysts, viz. the wide range of variation of their steric and electronic properties which can be adapted to the specific reaction at hand, can be exploited for tailoring highly effective catalysts. Moreover, the mode of action of these homogeneous catalysts remains understandable as a model and under the reaction conditions chosen - in complete contrast to the case of many heterogeneous catalytic systems. The first successful industrial application of water-soluble catalysts was in the oxo process of Ruhrchemie/Rhone Poulenc. The following article reports on ten years' experience with this process and the HRh(CO)[P(m-sulphophenyl-Na)3]3 catalyst.