Materials, Methods & Technologies, Volume 6, 2012

Rezumat: In this work an approach to obtain effective and easy reusable heterogeneous catalyst, LbL deposition of polyelectrolytes followed by covalently binding with cobalt (II) and copper (II) ions were described. Immobilization of metal complexes via covalent attachment to insoluble template is an attractive method to facilitate catalyst recovery, recycling. The reaction in the heterogeneous catalysis goes in the interface of catalyst and reaction solution and it is important to create a catalyst with large surface area. We have used polycations as polyethyleneimine (BPEI), quɚternized poly(4- vynilpyridine) (QPVP) and polyanions as poly(acrylic acid) (PAA), poly(styrene sulphonate) sodium salt (PSS) and the electrostatic layer-by-layer assembly technique to make uniform thin film coating on SiO2 nanoparticles and glass slides with controllable thickness, roughness and mechanically durability. The stability of metals within multilayers in reaction condition were tested. We compared the amount of metal in PEMs of different polyelectrolytes. The stability constants of complexforming processes of the polymer-metal complexes in water and in alcohol were calculated by modified method of Bjerrum. Catalytic activity of immobilized catalysts was investigated for oxidation of toluene by molecular oxygen. Catalysts were separated from reaction mixture easily and had been used for this reaction five times without significant loss of activity.