15205-66-0Relevant articles and documents
Rowland et al.
, p. 451,456 (1968)
Sandwich type polyoxometalates encapsulated into the mesoporous material: Synthesis, characterization and catalytic application in the selective oxidation of sulfides
Naseri, Elham,Khoshnavazi, Roushan
, p. 28249 - 28260 (2018/08/16)
The A-type sandwich polyoxometalates of [(HOSnIVOH)3(PW9O34)2]12- (P2W18Sn3) and [(OCeIVO)3(PW9O34)2]12- (P2W18Ce3) were immobilized for the first time into the porous metal-organic framework MIL-101(Cr). FT-IR, powder X-ray diffraction, SEM-EDX, ICP analysis, N2 adsorption and thermogravimetric analysis collectively confirmed immobilization and good distribution of polyoxometalates into cages of MIL-101(Cr). The catalytic activities of the homogeneous P2W18Sn3 and P2W18Ce3 and the corresponding heterogeneous catalysts were examined in the oxidation of sulfides to sulfones with H2O2 as the oxidant at room temperature. The effects of different dosages of polyoxometalates, type of solvent, reaction time, amount of catalyst and oxidant in this catalytic system were investigated. The new P2W18Sn3@MIL-101 and P2W18Ce3@MIL-101 nanocomposites exhibited good recyclability and reusability in at least five consecutive reaction cycles without significant loss of activity or selectivity.
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
Gholamyan, Sahar,Khoshnavazi, Roushan,Rostami, Amin,Bahrami, Leila
, p. 71 - 81 (2017/02/10)
Abstract: Sandwich-type polyoxometalates of [M4(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 [Mn4(XW9O34)2]10?(X = P5+, As5+) supported on Tb/TiO2which 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%. Graphical Abstract: [Figure not available: see fulltext.]