Abstract: The thermoregulated PEG (polyethylene glycol) biphasic catalytic system, which has a characteristic of “being homogeneous at high temperature and biphasic at room temperature★, was applied for the hydroformylation of tripropene catalyzed by Rh(acac)(CO)2/TMPGP (TMPGP: P[O(CH2CH2O)nCH3]3, n=8). The effects of reaction conditions on the reaction and the catalyst recycling efficiency were studied systematically. Under the optimized reaction conditions (V(CO)/V(H2)=1, 6 MPa, and 130 ℃), tripropene conversion and aldehyde yield reached 77% and 75%, respectively. The PEG phase containing the catalyst was separated at room temperature and recycled 11 times without significant loss of catalytic activity. The Rh leaching into the product phase in the first run was 1.5% (mass fraction), and the average Rh loss for each run of the 11 cycles was 0.69%. Further studies showed that the catalyst phase could be recycled 15 times without loss of catalytic activity when the whole catalytic system was cooled to-20℃, and the Rh leaching into the product phase was only 0.16% in the first run.

Key words: polyethylene glycol, thermoregulated PEG biphasic catalysis, rhodium, tripropene, hydroformylation