Pillared anionic clays or layered double hydroxides were prepared by means of hydrothermal ion exchange reaction of [Zn 2Al(OH) 6]NO 3· x H 2O (ZnAl NO 3) with [GaW 11 O 39 M(H 2O)] 7- (abbr...Pillared anionic clays or layered double hydroxides were prepared by means of hydrothermal ion exchange reaction of [Zn 2Al(OH) 6]NO 3· x H 2O (ZnAl NO 3) with [GaW 11 O 39 M(H 2O)] 7- (abbreviated as GaW 11 M, M=Mn 2+ , Co +2 or Ni 2+ ). The layered compounds were characterized by means of XRD, IR, elemental analysis and DTA. The X ray diffraction and IR spectra show that the new anionic clays synthesized are layered compounds with the gallery heights of 0.99-1.00 nm and the Keggin structure tungstogallic heteropolyanions almost completely replace the interlayer NO - 3, entering the layer and retain their Keggin structure. The DTA gives a thermostability order of ZnAl GaW 11 Ni >ZnAl GaW 11 Co>ZnAl GaW 11 Mn>ZnAl NO 3. The ctalytic tests showed that the new pillared compounds have higher catalytic activities in the cyclooxidation reaction of maleic acid.展开更多
文摘Pillared anionic clays or layered double hydroxides were prepared by means of hydrothermal ion exchange reaction of [Zn 2Al(OH) 6]NO 3· x H 2O (ZnAl NO 3) with [GaW 11 O 39 M(H 2O)] 7- (abbreviated as GaW 11 M, M=Mn 2+ , Co +2 or Ni 2+ ). The layered compounds were characterized by means of XRD, IR, elemental analysis and DTA. The X ray diffraction and IR spectra show that the new anionic clays synthesized are layered compounds with the gallery heights of 0.99-1.00 nm and the Keggin structure tungstogallic heteropolyanions almost completely replace the interlayer NO - 3, entering the layer and retain their Keggin structure. The DTA gives a thermostability order of ZnAl GaW 11 Ni >ZnAl GaW 11 Co>ZnAl GaW 11 Mn>ZnAl NO 3. The ctalytic tests showed that the new pillared compounds have higher catalytic activities in the cyclooxidation reaction of maleic acid.
