Hydrogenation of citral on activated carbon and high-surface-area graphite-supported ruthenium catalysts modified with iron

The hydrogenation of citral has been performed over Ru-Fe catalysts supported on activated carbon and on high-surface-area graphite. It was found that selectivity to unsaturated alcohols is independent of the carbonaceous support used for ruthenium catalysts. The addition of iron enhances selectivity to unsaturated alcohols (geraniol and nerol) in a manner similar for both ruthenium catalysts, becoming maximum for the highest iron loading. Calorimetric experiments give some evidence about alloy formation in ruthenium catalysts promoted with iron. It is inferred that the surface polarity of the alloyed particles promotes the selective hydrogenation of citral toward unsaturated alcohols. (C) 2001 Elsevier Science.