posted on 2013-08-28, 00:00authored byLorenza Gardella, Andrea Basso, Mirko Prato, Orietta Monticelli
In
this work, a novel catalytic system is developed, consisting
of palladium nanoclusters homogenously dispersed on the surface of
nanostructured polymer nanofibers based on poly(L-lactic acid) (PLLA)
and polyhedral oligomeric silsesquioxanes (POSS). Indeed, PLLA nanofibers
containing amino-functionalized silsesquioxane molecules (POSS-NH2), potentially capable of interacting with the metal precursor,
are prepared by means of electrospinning. Conversely to the polymer
matrix, which does not show any tendency to retain the metal precursor,
the submicrometric dispersion of POSS-NH2 in the PLLA nanofibers,
as demonstrated by SEM-EDS analysis, turns out to promote the formation
of metal nanoclusters. TEM measurements show a uniform distribution
of Pd nanoparticles, characterized by an average dimension of ca.
4 nm, along the fibers. The prepared system proves a relevant catalytic
activity toward the hydrogenation of stilbene under heterogeneous
conditions. Moreover,
as demonstrated by XPS measurements, the support is capable of retaining
the catalyst during the hydrogenation reaction, thus preventing its
leaching.