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研究了浸渍偏钨酸铵和仲钼酸铵的无定形ＺｒＯ２在焙烧过程中钨和钼氧化物表面分散和晶相变化情况．发现于３５０℃焙烧后钨、钼仍以多聚酸根形式分散于ＺｒＯ２表面，用ＸＲＤ法测定的“视阈值”远大于按ＷＯ３和ＭｏＯ３计算的单层分散容量．８００℃焙烧后钨和钼以ＷＯ３和ＺｒＭｏ２Ｏ８的形式分散于ＺｒＯ２表面上，用ＸＲＤ方法测定的“视阈值”与ＷＯ３和ＺｒＭｏ２Ｏ８的单层分散容量相近．Ｈａｍｍｅｔｔ指示剂法和正戊烷异构化反应结果表明，ＷＯ／ＺｒＯ２体系的Ｈｏ可达－１３．８～－１４．５，ＭｏＯ３／ＺｒＯ２体系的Ｈｏ可达－１２．０～－１２．７．８００℃焙烧的ＷＯ３和ＭｏＯ３含量在单层分散容量附近的样品超强酸性最强．
The surface dispersion and phase changes of tungsten and molybdenum oxides during the calcination of amorphous ammonium zirconium tungstate and ammonium paramolybdate were investigated. It is found that tungsten and molybdenum still disperse on the surface of ZrO2 as polyacid at 350 ℃. The “apparent threshold” measured by XRD is much larger than the monolayer dispersion calculated by WO3 and MoO3. After roasting at 800 ℃, tungsten and molybdenum are dispersed on the surface of ZrO2 in the form of WO3 and ZrMo2O8. The “apparent threshold” measured by XRD method is similar to the monolayer dispersion capacity of WO3 and ZrMo2O8. The results of Hammett indicator method and n-pentane isomerization show that the Ho of the WO / ZrO2 system reaches -13.8 ~ -14.5 and the Ho of the MoO3 / ZrO2 system reaches -12.0 ~ -12.7. The samples with WO3 and MoO3 calcined at 800 ℃ had the strongest super acidity in the vicinity of the monolayer dispersion capacity.