Organic-anion-pillared layered double hydrotalcites such as Zn2AlTA(TA=terephthalate) are easily synthesized by using coprecipitation reaction of Zn2+ and Al3+ ions with terephthalic acid in NaOH solution. Exchange of...Organic-anion-pillared layered double hydrotalcites such as Zn2AlTA(TA=terephthalate) are easily synthesized by using coprecipitation reaction of Zn2+ and Al3+ ions with terephthalic acid in NaOH solution. Exchange of this material under mild acidic conditions with the heteropolyanions proceeds smoothly to yield Zn2AlSiW11 Co and Zn2Al-BW11Cu. Characterization has been carried out by elemental chemical analysis, powder X-ray diffeaction and IR spectra. The results indicated that these materials possess exceptionally well-ordered gallery height of 0.98 nm. It was found that this kind of pillared layered catalyst has high activity and selectivity for the oxidation of benzaldehyde to benzoic acid using H2O2 as oxidant in liquid-solid phase system.展开更多
Layered double hydrotalcites pillared by het erop olyoxometates, ZnAl- GeW11Z (Z=Ni2+, Cu2+) and ZnAl-GeW11 have been synhesized by ion exchange. A procedure for intercalating layered double hydroxides is described in...Layered double hydrotalcites pillared by het erop olyoxometates, ZnAl- GeW11Z (Z=Ni2+, Cu2+) and ZnAl-GeW11 have been synhesized by ion exchange. A procedure for intercalating layered double hydroxides is described in this paper, powder X-ray diffraction and IR spectra measuremnts confirm that for GeW11O39Z (H2O)6- and GeW11O8-39intercalation takes place and the gallery heights are of 9.9A. The new compounds are found to be calalytically efficient for the esterification of acetic acid with n-butanol in liquld-phase.展开更多
文摘Organic-anion-pillared layered double hydrotalcites such as Zn2AlTA(TA=terephthalate) are easily synthesized by using coprecipitation reaction of Zn2+ and Al3+ ions with terephthalic acid in NaOH solution. Exchange of this material under mild acidic conditions with the heteropolyanions proceeds smoothly to yield Zn2AlSiW11 Co and Zn2Al-BW11Cu. Characterization has been carried out by elemental chemical analysis, powder X-ray diffeaction and IR spectra. The results indicated that these materials possess exceptionally well-ordered gallery height of 0.98 nm. It was found that this kind of pillared layered catalyst has high activity and selectivity for the oxidation of benzaldehyde to benzoic acid using H2O2 as oxidant in liquid-solid phase system.
文摘Layered double hydrotalcites pillared by het erop olyoxometates, ZnAl- GeW11Z (Z=Ni2+, Cu2+) and ZnAl-GeW11 have been synhesized by ion exchange. A procedure for intercalating layered double hydroxides is described in this paper, powder X-ray diffraction and IR spectra measuremnts confirm that for GeW11O39Z (H2O)6- and GeW11O8-39intercalation takes place and the gallery heights are of 9.9A. The new compounds are found to be calalytically efficient for the esterification of acetic acid with n-butanol in liquld-phase.