DEVELOPMENT OF LA(X)MO(Y) NANOPARTICLES DISPERSED IN A LAYERED SILICATE MATRIX

Stoichiometric La(x)M(fsa)(2)en,NO3 . H2O heterobinuclear complexes (M = Ni, Cu, Co; (fsa)(2)en = N,N'-bis (3-carboxysalicydene)ethylene dia mine) were synthesized by a careful control of pH during the two steps of the complexation. In the case of nickel and cobalt, the thermal tr eatment of these complexes led to well crystallized LaNiO3 or LaCoO3 p erovskite type phases, whereas a La2CuO4 type structure was obtained f rom the La-Cu complex. Whatever M, the oxide phases are formed at much lower temperatures than needed by classical methods. The cell paramet ers of these structures are in good agreement with data given in the l iterature. A large interlayer distance expand was induced by exchangin g the sodium cations of montmorillonite with the La(x)M(fsa)(2)en cati ons, c. from 12.5 Angstrom to approximate to 23.5 Angstrom. Lamellar s ilicate/oxide nanocomposites were formed by heating the Mont/La(x)M(fs a)(2)en under air atmosphere at 400 degrees C. These new materials cou ld have important applications for selective oxidizing catalysis.