Hydroformylation by using rhodium tethered on selectively functionalized silica and high-pressure IR study

In this study, selective surface functionalization was performed with amine functional groups by post toluene reflux condition over MCM-41. This material was used as a support for rhodium immobilization. The selective functionalized MCM-41-based heterogeneous catalysts were applied toward the 1-octene hydroformylation. MCM-41 materials with amine and Rh complexes in the intra-pores show a higher selectivity for linear aldehydes. The mesopore, the steric bulky triphenylphosphine ligand greatly improved the selectivity of the less hindered linear aldehydes over the branched aldehyde. The active species involved in the hydroformylation has been studied by in situ FT-IR. The active species containing Rh(CO)₂(PPh₃)₂ and HRh(CO)(Ph3P)3 were involved in the hydroformylation of 1-octene over the heterogeneous catalyst systems.