【摘要】 用ＸＲＤ，ＦＴＲａｍａｎ，比表面积测定等方法研究了Ｚｒ（ＳＯ４）２的热分解行为及所形成超强酸位的结构，用正己烷低温裂解和异构化反应测定了焙烧温度与超强酸性的关系．结果表明，其超强酸位结构与ＳＯ２－４／ＺｒＯ２相同，即ＳＯ２－４桥式双齿结合于ＺｒＯ２（ｔ）上．由于温度较低时Ｚｒ（ＳＯ４）２分解不完全，而到达Ｚｒ（ＳＯ４）２彻底分解所需的高温时，主要生成ＺｒＯ２（ｍ），残留在表面的ＳＯ２－４极少，所以Ｚｒ（ＳＯ４）２的超强酸性受到很大限制．实验结果证明，Ｚｒ（ＳＯ４）２能在ＳｉＯ２上分散，分散阈值约为２６ｍｇ／ｍ２．处于分散态的Ｚｒ（ＳＯ４）２分解温度明显降低，有利于吸附态ＳＯ２－４的滞留．而且，只要Ｚｒ（ＳＯ４）２含量不超过分散阈值，分解出的ＺｒＯ２全部是四方相．因此，通过负载方法可使Ｚｒ（ＳＯ４）２的超强酸性得到明显的改善．更多还原

【Abstract】 The thermo decomposition behavior of Zr（SO₄）₂ and the structure of its superacid sites have been studied by using XRD, FT Raman and the measurement of its specific surface area. The relationship between superacidity and calcination temperature is determined by means of cracking and isomerization of n C₆H₁4 at low temperature. The results show that the structure of superacid sites is similar to that of SO 2- 4/ZrO 2, i.e. , SO 2- 4 is combined with tetragonal ZrO 2（t） in bridging bidentate state. The decomposition of Zr（SO 4） 2 is not complete at low temperature, while most of the decomposition product is monoclinic ZrO 2（m） and SO 2- 4 retained on the surface is few at the temperature high enough to decompose Zr（SO 4） 2 thoroughly. Therefore, the superacidity of calcined Zr（SO 4） 2 is limited to a great extent. The experiments prove that Zr（SO 4） 2 can disperse on SiO 2 surface and its dispersion threshold is about 2 6 mg/m 2. Since the decomposition temperature of Zr（SO 4） 2 dispersed on SiO 2 is lower than that of crystalline Zr（SO 4） 2, more SO 2- 4 in adsorbed state can be retained, and all of ZrO 2 obtained is tetragonal only if the content of Zr（SO 4） 2 does not exceed the threshold. By this way, the superacidity of Zr（SO 4） 2 is improved.更多还原