GAS-PHASE HYDROFORMYLATION OF PROPENE CATALYZED BY A POLYMER BOUND RHODIUM(I) COMPLEX

The continuous gas phase hydroformylation of propene is catalyzed by a cationic rhodium carbonyl complex co-ordinatively bound to a copolymer of 2-vinylpyridine and methyl acrylate crosslinked with 5 mol% ethene diacrylate. The counter ion had a strong effect on both activity and deactivation. At 403 K and 1100 kPa total pressure (C3:CO:H-2=2.4:2.2:1.0) the total initial rate was 8.5 x 10(-7) mol/ (s gRh) with tetraphenylborate as counter ion. The regioselectivity was close to 1. The catalyst rapidly lost about 50% of its initial activity. Deactivation was accompanied by benzene formation, indicating a reaction of the tetraphenylborate counter ion with traces of water. As benzene formation diminished, deactivation slowed down. A catalyst with chloride as charge balancing ligand was less active and needed activation at higher temperatures than the tetraphenylborate complex. Only slow deactivation was observed with this catalyst.