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
A series of organic anion-pillared hydrotalcites were synthesized by the ion exchange method and characterized by X-ray diffraction and Fourier transform infrared spectroscopy.The hydrotalcite precursor and pillared h...A series of organic anion-pillared hydrotalcites were synthesized by the ion exchange method and characterized by X-ray diffraction and Fourier transform infrared spectroscopy.The hydrotalcite precursor and pillared hydrotalcites with different anions was tested as catalysts in transesterification of dimethyl carbonate（DMC） with phenol.The results show that the catalytic selectivity of this transesterification reaction over these organic anion-pillared hydrotalcites is significantly improved.The catalytic selectivities of C4H4O4-,C6H8O4-,C10H16O4-,（1,4-）C8H4O4-,and C7H5O2-pillared hydrotalcites for transesterified products（diphenyl carbonate and methyl phenyl carbonate） are all greater than 90%,at least 10% higher than that of the hydrotalcite precursor.Under the conditions of（n（phenol））/（n（DMC））=4,catalyst amount=1.5%,and t=10 h,the C6H8O4-pillared hydrotalcite presents the best catalytic performance,and the DMC conversion and the selectivity for transesterified products reach 43.8% and 93.2%,respectively.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A series of organic anion-pillared hydrotalcites were synthesized by the ion exchange method and characterized by X-ray diffraction and Fourier transform infrared spectroscopy.The hydrotalcite precursor and pillared hydrotalcites with different anions was tested as catalysts in transesterification of dimethyl carbonate（DMC） with phenol.The results show that the catalytic selectivity of this transesterification reaction over these organic anion-pillared hydrotalcites is significantly improved.The catalytic selectivities of C4H4O4-,C6H8O4-,C10H16O4-,（1,4-）C8H4O4-,and C7H5O2-pillared hydrotalcites for transesterified products（diphenyl carbonate and methyl phenyl carbonate） are all greater than 90%,at least 10% higher than that of the hydrotalcite precursor.Under the conditions of（n（phenol））/（n（DMC））=4,catalyst amount=1.5%,and t=10 h,the C6H8O4-pillared hydrotalcite presents the best catalytic performance,and the DMC conversion and the selectivity for transesterified products reach 43.8% and 93.2%,respectively.
