Both the cubic and orthorhombic ZrW0.8Mo1.2O8 were prepared by precursor-microwave route. The cubic phase belonged to a-ZrW2O8 structure type and the orthorhombic phase was refined with the structural model of LT-ZrMo...Both the cubic and orthorhombic ZrW0.8Mo1.2O8 were prepared by precursor-microwave route. The cubic phase belonged to a-ZrW2O8 structure type and the orthorhombic phase was refined with the structural model of LT-ZrMo2O8 by the Rietveld method. The orthorhombic phase belonged to Pmn21 space group and the cell parameters were ao=0.597 1(9) nm, bo=0.730 6(1) nm, co=0.912 7(1) nm, Rp%=9.37; wRp%=11.81. The TEM images were also given. The comparison was made between precursor-heated and precursor-microwave routes. Metastable polymorphic phase was favorably formed by the latter method.展开更多
The precursor ZrW1.6Mo0.4O7(OH)2(H2O)2 was characterized by IR and XRD methods. δ′-ZrW1.6Mo0.4O8 was prepared by careful controlling the annealing conditions from the precursor and was determined to have the formula...The precursor ZrW1.6Mo0.4O7(OH)2(H2O)2 was characterized by IR and XRD methods. δ′-ZrW1.6Mo0.4O8 was prepared by careful controlling the annealing conditions from the precursor and was determined to have the formula as o-ZrW1.6Mo0.4O8·H2O by TG-DSC, IR, and XRD methods. The relation between o-ZrW1.6Mo0.4O8·H2O and o-ZrW1.6Mo0.4O8 was discussed through variable temperature XRD patterns. Further more, the mechanism of the precursor dehydration was suggested.展开更多
文摘Both the cubic and orthorhombic ZrW0.8Mo1.2O8 were prepared by precursor-microwave route. The cubic phase belonged to a-ZrW2O8 structure type and the orthorhombic phase was refined with the structural model of LT-ZrMo2O8 by the Rietveld method. The orthorhombic phase belonged to Pmn21 space group and the cell parameters were ao=0.597 1(9) nm, bo=0.730 6(1) nm, co=0.912 7(1) nm, Rp%=9.37; wRp%=11.81. The TEM images were also given. The comparison was made between precursor-heated and precursor-microwave routes. Metastable polymorphic phase was favorably formed by the latter method.
文摘The precursor ZrW1.6Mo0.4O7(OH)2(H2O)2 was characterized by IR and XRD methods. δ′-ZrW1.6Mo0.4O8 was prepared by careful controlling the annealing conditions from the precursor and was determined to have the formula as o-ZrW1.6Mo0.4O8·H2O by TG-DSC, IR, and XRD methods. The relation between o-ZrW1.6Mo0.4O8·H2O and o-ZrW1.6Mo0.4O8 was discussed through variable temperature XRD patterns. Further more, the mechanism of the precursor dehydration was suggested.
