AN INSITU INFRARED STUDY OF ETHYLENE HYDROFORMYLATION AND CO HYDROGENATION ON RU/SIO2 AND SULFIDED RU/SIO2

Ethylene hydroformylation, CO hydrogenation and CO adsorption on Ru/SiO2 and sulfided Ru/SiO2 were studied by in situ infrared spectroscopy. Ethylene hydroformylation was shown to occur on the surface of Ru/SiO2 and sulfided Ru/SiO2 catalysts. Increasing reaction pressure slightly increased the infrared absorbance of linear CO and greatly enhanced selectivities and activities for the formation of acetaldehyde and propionaldehyde in CO hydrogenation and ethylene hydroformylation, respectively. No relation between the IR spectra of adsorbed CO and the hydroformylation activity was observed. Sulfidation of Ru/SiO2 led to a decrease in the wavenumber and absorbance of linearly adsorbed CO and to the inhibition of CO hydrogenation, ethylene hydrogenation and ethylene hydroformylation. Transient and temperature-programmed reaction studies revealed that sulfur poisoning of the Ru/SiO2 catalyst for ethylene hydroformylation was due primarily to the inhibition of desorption of propionaldehyde from the sulfided Ru/SiO2. The presence of residual chlorine on the Ru/SiO2 resulted in an appreciable decrease in the hydrocarbon synthesis activity but only a slight modification of the IR band for the adsorbed CO.