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. ...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.展开更多
Mg-Al hydrotalcites with different Mg/Al ratios and their polyoxometalateintercalates were synthesized by direct ion-exchange reactions. The porous structures ofthe pillared products were studied by adsorbing various ...Mg-Al hydrotalcites with different Mg/Al ratios and their polyoxometalateintercalates were synthesized by direct ion-exchange reactions. The porous structures ofthe pillared products were studied by adsorbing various molecules with different, kineticdiameter on them. The results show that the porous structures of the pillared productscan be adjusted either by changing the layer charge densities or by changing the pillardensities, i. e. the pore diameter will increase with the increament of the Mg atoms inthe layers and the polyoxometalate charges in the gallery.展开更多
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 discus...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.展开更多
文摘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.
文摘Mg-Al hydrotalcites with different Mg/Al ratios and their polyoxometalateintercalates were synthesized by direct ion-exchange reactions. The porous structures ofthe pillared products were studied by adsorbing various molecules with different, kineticdiameter on them. The results show that the porous structures of the pillared productscan be adjusted either by changing the layer charge densities or by changing the pillardensities, i. e. the pore diameter will increase with the increament of the Mg atoms inthe layers and the polyoxometalate charges in the gallery.
文摘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.
