Immobilized Sandwich-Type Polyoxometalates [Mn4(XW9O34)2]n- on Tb-Doped TiO2 Nanoparticles as Efficient and Selective Catalysts in the Oxidation of Sulfides and Alcohols

Sandwich-type polyoxometalates of [M-4(XW9O34)(2)](n-) (M = Mn2+, Cu2+, Zn2+, X = Ge4+, P5+, As5+) supported on Ln-doped TiO2 (Ln = Nd3+, Sm3+, Tb3+ and Dy3+) nanoparticles were prepared and their catalytic activities examined for oxidation of sulfides and alcohols. Results show that the catalytic activities of new nanocomposites were significantly higher than homogeneous conditions with corresponding sandwich-type polyoxometalates. The best results obtained by [Mn-4(XW9O34)(2)](10-) (X = P5+, As5+) supported on Tb/TiO2 which were characterized by various techniques. The catalysts can be easily recovered and reused for at least five times without obvious decrease of catalytic activities and the structures of the catalysts remain unchanged after recycling and the yields for catalyst recovery are all above 95%. [GRAPHICS]