PRIN 2008

2010 - 2012
Title: 
Novel nanostructured metal-functional polymer catalysts with enhanced performances in carbonylation, hydrogenation and oxidation reactions
Principal Investigator: 
Francesco Ciardelli
Project type: 
National

Abstract

The present project is mainly devoted the understanding the real possibility to develop catalysts based on metal nanoparticles with performances modulated by the appropriate combination of the well known unique features of nanosized metal powder with the physical and chemical contribution deriving by selected polymers. These last are expected to act as stabilizing agents but also to confer the metal species some features of homogeneous catalysis (i.e. ligand effect) and facilitate the shaping of the catalyst particles in an appropriate form for their use in industrial catalytic reactors. This last effect will be developped also looking to the use of inorganic supports, where the polymer will act as "adhesive" for the metal particles thus avoiding leaching and change of particles dimensions. To this objective the project, taking advantage of the complementary expertise of the insolved research groups, will perform research activity including: 1) preparation of mono or bimetallic nanoparticles NP (1-5 nm) by different and innovative methods of gold, ruthenium, and palladium, 2) supportation/embedments of the NP on/to polymer matrices acting as stabilizers ,active support or cocatalysts, also in combination with inorganic supports; 3) comparative testing of the prepared catalysts in a selected group of reaction of great general interest such as oxidation, hydrogenation and carbonylation of selected substrates. As far as NP preparation of NP is concerned, three different methods will be used: the first method involves modified chemical reduction , the second method the
chemical reduction assisted by microwaves irradiation (using a special coaxial emitter of microwaves power placed directly inside the reactants)or laser ablation, and the third method the co-condensation at low temperature of metallic vapours with weakly coordinating solvent (Metal Vapour Synthesis, MVS). Suitable polymeric matrices will be prepared to be employed as templating agents for the synthesis of metal nanoparticles (i.e. polyketones, functionalized polyolefins, self assembling block copolymers (such as PS-b-PMMA), peptides,and polymer gels. The metal NP with the polymer ligand will be also supported on the surface of modified inorganic matrices.
The products obtained in the preparative steps will be characterized by several techniques such as GPC, FT-IR spectroscopy, 1H- and 13C-NMR spectrometry, X-Ray, diffraction and SEM, TEM or DMA microscopy. Size-controlled nanoparticles of noble metals, stabilized by microgels will be used for heterogeneous catalysts formed by size-controlled metal nanoclusters supported on either cross-linked, gel-type, organic co-polymers (resins) or inorganic oxides, such as silica, will be employed for selective hydrogenation reactions. NP from Au and Au-Pd with different structures in term of preparation and polymer ligand or inorganic support will be tested for the oxydation of primary and secondary alcohols to carbonylic compounds . Ru and Pd NP will be supported on sulfonic resins, which act at the same time as the support, agent for size-control in the generation of metal nanoparticles and carrier of the acid-base catalytic functionality will be used as bifunctional catalysts for the one-pot hydrogenolysis of glycerol to 1,2-propanediol. Polyketones modified with chiral peptides will be used to induce a dysymmetric structure on Pd NP to be used in the enantioselective hydrogenation and
carbonylation reaction of chiral or prochiral substrates.