The influence of triphenylphosphine trisulfonate (TPPTS) ligands on the catalytic activity of the supported ionic liquid-phase catalysts for the hydroformylation of ethylene

Triphenylphosphine trisulfonate (TPPTS) is a common used ligand for homogeneous hydroformylation of olefins with Rh complexes. The synthesis of the TPPTS ligand is a rather complex procedure and it is influenced by several factors. In this work, the influence of pH on the synthesis of the TPPTS ligand was thoroughly studied and a neutralization pH of 5.5–6.5 was optimized for a successful synthesis of TPPTS-Cs 3 and TPPTS-Na 3 ligands. The catalytic activity of the corresponding Rh-TPPTS supported ionic liquid-phase (SILP) catalysts with SiO 2 and TiO 2 supports were studied for the continuous, fixed-bed gas-phase hydroformylation of ethylene to propanal. The SILP catalyst with TPPTS-Cs 3 on SiO 2 support exhibited superior catalytic activity compared to a corresponding catalyst with TPPTS-Na 3 , while the activity of the latter catalyst was found to be much higher than an analogous catalyst based on TiO 2 support. Combined this clearly emphasizing the importance of both ligand and support characteristics in the SILP hydroformylation system.