Industrial & Engineering Chemistry Research, Vol.44, No.14, 4973-4981, 2005
Analysis of the hydroformylation reaction over an immobilized catalyst in supercritical carbon dioxide
Homogeneously catalyzed reactions are often among the most selective reactions that can be accomplished, yet they are often unsuitable for industrial applications because recovery of the expensive catalyst can be difficult. Many schemes have been developed to circumvent this problem. We have attempted to simplify catalyst recovery by grafting a homogeneous catalyst onto a solid support and utilizing this supported catalyst in combination with a supercritical fluid to reduce the phase-transfer effects that often inhibit the performance of supported catalysts. When used for the hydroformylation of 1-hexene, we demonstrate that the performance of the catalyst can be varied using traditional methods from homogeneous catalysis, heterogeneous catalysis, and reactions in supercritical fluids. Catalyst performance is compared over several sets of conditions, and the surface mechanism is probed using high-pressure diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results suggest that the homogeneous mechanism is effectively transferred to the supported material.