Hydrogenation of dehydrolinalool with novel catalyst derived from Pd colloids stabilized in micelle cores of polystyrene-poly-4-vinylpyridine block copolymers

Hydrogenation of triple bond of dehydrolinalool to double one of linalool w as studied with Pd colloids prepared in polystyrene-poly-4-vinylpyridine mi celles in toluene and deposited on Al2O3. The high selectivity (99.8%) of t his catalyst is explained by durable modification of the Pd nanoparticle su rface with 4-vinylpyridine units. The activity of Pd catalyst studied is de termined by high reactivity of small Pd nanoparticles. The influence of sol vent nature on catalytic properties of Pd colloidal catalyst is studied. Ma ximum relative rate was found to be in methanol, but the highest selectivit y was achieved in toluene because the latter is a selective solvent for pol ystyrene-poly-4-vinylpyridine micelles and provides the better accessibilit y of reactive sites. (C) 1999 Elsevier Science B.V. All rights reserved.