Loading silica with metals (palladium or platinum) under mild conditions by using well-defined molecular precursors

The loading of pre-treated amorphous silica with platinum or palladium was carried out by using the molecular precursors Pt2(mu-Cl)2Cl2(CO)2, or Pd2(mu-Cl)2Cl2(CO)2, respectively, which contain the required amount of coordinated CO to carry out the formation of the metal particles upon contact with moisture. The reactivity of the well-soluble mononuclear platinum complex cis-PtCl2(CO)2 with stoichiometric amounts of water was investigated either under N2 or CO. The metal nanoparticles produced on the silica matrix have been characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The catalytic performance of the silica-supported metals thus produced was evaluated in the hydrogenation of cyclohexene.