A comparative study of supported aqueous- and ethylene glycol-phase catalysts in stilbene hydrogenation: Influence of the different modes of dispersion of supported liquids

Abstract

Supported liquid phase catalysts (SLPC) containing water-soluble Pd complexes were used for hydrogenation of stilbene in toluene. When water is loaded on a silica gel support, the catalytic activity of SLPC increases with the amount of the water. In contrast, when ethylene glycol (EG) is used as the supported liquid, the activity does not depend on the amount of EG loaded. These results can be explained by differences in the mode of dispersion of the supported liquids over the support.

Selective hydrogenation of unsaturated aldehydes in a poly(ethylene glycol)/compressed carbon dioxide biphasic system

“…The immobilization of homogeneous catalysts was proposed to resolve the above problems, and for organometallic complex catalysts, they are usually immobilized in water, 6-8 ionic liquid, 9 fluorous liquid 10 or ethylene glycol 11 and the reactants and products are usually contained in organic phase. In the water-organic system, the catalysts must be modified to be sufficiently soluble in water, and the activity and/or selectivity of the water-soluble catalysts are normally lower than those of the organo-soluble parent catalysts.…”