Characterization and hydroformylation performance of mesoporous MCM-41-supported water-soluble Rh complex dissolved in ionic liquids

The TPPTS-Rh complex [TPPTS = trisodium salt of tri-(m-sulfophenyl)-phosphine, P(m-C6H4SO3Na)3], which was dissolved in the ionic liquids 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMI⋅BF4), 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMI⋅PF6), and 1,1,3,3-tetramethylguanidinium lactate (TMGL), was immobilized on MCM-41. The resulting supported ionic liquid-phase catalysts (SILPCs) were very active for the hydroformylation of higher olefins. The SILPCs with the regular hexagonal array of MCM-41 were structurally stable before and after the catalytic reaction, as characterized by XRD, N2 adsorption/desorption, FTIR, 31P-NMR, SEM, HRTEM, and TGA-DSC. The obtained SILPCs showed higher catalytic activity, independent of IL type, as compared with their ionic liquid–organic biphasic counterparts and the one with SiO2 as carrier. Such SILPCs could be reused several times without significant loss of activity or selectivity.