A biguanide/Pd-decorated SBA-15 hybrid nanocomposite: Synthesis, characterization and catalytic application

A stable palladium-decorated SBA-15 nanocomposite was simply fabricated through surface modification of SBA-15 with biguanide and subsequent metal/ligand coordination with Pd2+ from inexpensive commercially available starting materials and using standard laboratory techniques. The structure of this organic inorganic hybrid material was characterized by SEM, TEM, XRD, elemental analyzer, atomic absorption spectroscopy, N2 adsorption–desorption (BET), and FT-IR techniques. The catalytic performance of this novel heterogeneous catalyst was determined for the Suzuki cross-coupling and aerobic oxidation of benzyl alcohols. The composite exhibited an excellent catalytic activity and reuse ability of various recycles in air for the aforementioned organic transformations. TEM images of the recovered catalyst showed retained ordered mesostructure of SBA-15 with no damage in the periodic structure of the silicate framework and a good dispersion of in situ generated palladium nanoparticles within the SBA-15 structure.

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► Coordination of Pd(II) ions on SBA-15-supported biguanide.
► SBA-15-Met-Pd(II) catalyzes Suzuki reaction in aqueous media.
► Pd nanoparticles are generated in situ during the Suzuki reaction.
► Palladium-decorated superbasic heterogeneous silica catalyst.
► Supported Pd nanoparticles with excellent stability and recyclability.