SELECTIVE SYNTHESIS OF ALCOHOLS FROM SYNGAS AND HYDROFORMYLATION OF ETHYLENE OVER SUPPORTED CLUSTER-DERIVED COBALT CATALYSTS

Hydroformylation of ethylene and CO hydrogenation were studied over co balt-based catalysts derived from reaction of Co-2(CO)(8) with ZnO, Mg O and La2O3 supports. At 433 K a similar activity sequence was reached for both reactions: Co/ZnO > Co/La2O3 > Co/MgO. This confirms the dee p analogy between hydroformylation and CO hydrogenation into alcohols. In the CO hydrogenation the selectivity towards alcohol mixture (C-1- C-3) was found to be near 100% at 433 K for a conversion of 6% over th e Co/ZnO catalyst; this catalyst showed oxo selectivity higher than 98 % in the hydroformylation of ethylene. Magnetic experiments showed tha t no metallic cobalt particles were formed at 433 K. It is suggested t hat the active site for the step that is common to both reactions is r elated to the surface homonuclear Co2+/[Co(CO)(4)](-) ion-pairing spec ies.