Catalytic hydroformylation of 1-hexene over Co 2Rh 2(CO) 12 supported on inorganic carrier materials

Abstract

Co 2Rh 2(CO) 12 supported on alumina, silica, magnesium silicate or zeolites catalyses 1-hexene hydroformylation to C 7-aldehydes with good yields. The effects of different amines on the 1-hexene hydroformylation were studied with Co 2Rh 2(CO) 12 strongly bound on an alumina carrier. This catalyst converted 85% of 1-hexene to C 7-aldehydes. When Et 3N is added to the hydroformylation solution, the yield of C 7-alcohols was maximum at 97%. With other cocatalysts Et 2NH, aniline, pyridine or NH 3 the yields Of C 7-alcohols were 62%, 24%, 17% and 0%, respectively. When studying the influence of the amount of Et 3N, it was found that less amine was needed for good alcohol conversion when the catalyst was supported on alumina than on silica. On the whole, the Co 2Rh 2(CO) 12 catalyst supported either on silica, magnesium silicate or zeolite in the same reaction conditions in the presence of Et 3N gave very similar C 7-oxygenate yields (99%) as Co 2Rh 2(CO) 12 on alumina. However, the alcohol contents of the above C 7-oxygenate yields were much lower than in the case Of Co 2Rh 2(CO) 12 on alumina. A 4–5 wt.% metal content of a Co 2Rh 2(CO) 12—alumina—Et 3N or Et 2NH catalyst was optimum in 1-hexene hydroformylation for 17 h. A synthesis gas pressure of 50 bar and a temperature of 100 °C provided the optimum reaction conditions.