POM-LDHs with the composition of MAI-XW11ZO39(M=Zn, Mg; X=P, Si; Z=Mn2+, Fe2+, Co2+, Ni2+, Cu2+) were synthesized, and their catalytic properties for oxidation of cyclohexene in the presence of dioxygen were studied. The results obtained show that the oxidation of cyclohexene gives mainly α-H oxidation products, and the reaction activities greatly depend on the nature of the substituted transition metals in the POM pillars, i. e.,with different Z ions, the activity is in the order: Co2+～Cu2+～Mn2+》Ni2+～Fe2+. In addition, the central atom in the POM pillars has some effects on the oxidation of cyclohexene.The activity increases when P is used instead of Si. No obvious difference between the activities of ZnAl and MgAl layers were observed.
Layered double hydroxides (LDHs) pillared with heteropolyanions have been measured using XPS、IR、XRD spertra, and the interaction between layers and pillars discussed, The mechanism of pillars has been further discussed by XPS spectra.
