The catalytic performance in ethylene hydroformylation over SiO2, MgO, and carbon-supported Ru, Ru-Co, Ru-Mn, Ru-Cr, and Co carbonyl cluster-derived catalysts has been investigated, and it was found that the catalysts derived from Ru monometallic and Ru-Co bimetallic carbonyl clusters are active in ethylene hydroformylation. The presence of Co atoms in Ru-Co carbonyl clusters led to a remarkable increase in the rate of product formation, especially for oxygenates. The Ru-Mn bimetallic carbonyl cluster-derived catalyst showed similar conversion, but it exhibited poor activity and selectivity for oxygenates as compared with catalysts derived from Ru6C(CO)17. In contrast to the Ru6C(CO)17 carbonyl cluster-derived catalyst, the Ru-Cr bimetallic carbonyl cluster-derived catalyst exhibited very low activity and selectivity for ethane and oxygenates, indicating that the Cr sites in Ru-Cr bimetallic carbonyl cluster-derived catalyst have a poisoning effect on ethylene hydroformylation. The nature of support has been shown to have a large influence on the catalytic activity and selectivity of the resulting catalyst. The effect of Co promotion in Ru-Co carbonyl clusters on silica and carbon was much stronger than that on MgO. The nature of these Ru-Co/SiO2 catalyts has been investigated by infrared and X-ray photoelectron spectroscopes. The IR spectra of CO on reduced Ru-Co/SiO2 catalysts prepared from Ru-Co bimetallic carbonyl clusters exhibited bands at 1684 cm-1. The reaction of CO and H-2 with Ru-Co/SiO2 catalysts showed a band at 1584 cm-1. In situ IR spectra of the reaction of CO + H-2 + C2H4 on these reduced Ru-Co/SiO2 catalysts exhibited bands at 1585 and 1555 cm-1 shifting to 1540 and 1520 cm-1 by (CO)-C-13 isotopic effect, which are strongly related to the activity and selectivity for propanol and propaldehyde in ethylene hydroformylation.