The activity of homogeneous and heterogenized Rh(I) complexes in hydrogenation of alkenes

Abstract

Kinetics of liquid phase hydrogenation of alkenes catalysed by homogeneous Rh(I) complexes prepared in situ from di-μ,μ'-chloro-bis/di(cyclooctene)rhodium/ and 3-(triethoxysilyl)propyldiphenylphosphine and by heterogenised analogues anchored to silica have been studied. The reaction was found to be first order in hydrogen, alkene and catalyst. Compared to the soluble complexes, the supported catalyst turned out to be substantially more stable. At 0.3-0.6%Rh concentrations on the support, the activity of the catalyst was not affected by pore size within 4-10 nm region. The supported catalysts prepared by functionalization of the support followed by formation of the Rh complex were more active then their homogeneous analogues.