Controllable synthesis, characterization and catalytic performance of a divacant Keggin-type tungstosilicate dimer-estertin derivative.

ZHU Haotian; ZHANG Ranran; LI Mengxuan; SUN Yang; SU Fang; ZHANG Lancui

A vacancy Keggin-type dimer ester tin tungstosilicate derivative (C(NH 2 ) 3 ) 7 H 3.5 [K⊂ Ni(H 2 O) 2 (SnCH 2 CH 2 COO)((Ni(H 2 O)) 0.75 (WO) 0.25 )(Si 2 W 18 O 67 )]·6H 2 O (abbreviated as Si 2 W 18 -Ni-SnRCOO, R=CH 2 CH 2 )) was synthesized by conventional aqueous solution method and characterized by a series of physical and spectroscopic methods. Single crystal X-ray structural analysis showed that this polyoxometalate (POM) is a dimer tungstosilicate-based organic-inorganic hybrid compound containing Ni ions and cyclic carboxyl tin (SnRCOO) groups. Unexpectedly, the carboxyl O atom of SnRCOO acts as a bridge O atom between the POM framework and the NiO6 octahedron. The thermal and photocatalytic activities of Si 2 W 18 -Ni-SnRCOO were studied . As a homogeneous catalyst, the conversion rate of cyclohexanol oxidation to cyclohexanone was as high as 98%, and the degradation efficiency of 20 mg·L -1 rhodamine B (RhB) was 88%. The experimental results show that the introduction of carboxyethyltin groups significantly improves the catalytic activity of this POM-based catalyst. In addition, the composite of Si 2 W 18 -Ni -SnRCOO and TiO 2 enables the catalyst to be recycled, and its photocatalytic efficiency remains almost unchanged after five cycles.

CATALYTIC activity; CATALYSTS recycling; SINGLE crystals; PHOTOCATALYSTS; CRYSTAL structure

Journal of Molecular Science, 2024, Vol 40, Issue 5, p462

1000-9035

Academic Journal

10.13563/j.cnki.jmolsci.2024.05.111