Standardization of Solid Superacid of Sulfated Zirconia Prepared Using Zirconia Supplied by Catalysis Society of Japan

在此基础上，推荐了日本催化学会提供的JRC-ZRO-2和JRC-5作为催化剂制备的起始原料。氧化锆凝胶在30 0℃及以下硫化前应充分干燥。研究了平衡吸附法和硫酸铵捏合法两种制备方法。氧化锆凝胶在两个过程中都进行了硫酸盐化，重现性很高。采用非晶化凝胶可制得高比表面积、高硫酸盐含量的硫酸化氧化锆粉。硫酸铵捏合法的表面硫酸盐含量重现性较高。然而，有一种趋势是，与活性中心的形成无关的不必要的硫酸盐离子仍留在表面。推荐的焙烧温度为650℃。从炉内温度分布的原因来看，强烈建议在600℃的温度下焙烧，硫化氧化锆由于是在高温下焙烧，因此可以不加注意地保存。该方法无需前处理即可用于多种反应。最好在使用前通过加热除去吸附的水。由于在某些情况下观察到酸量的减少，避免了在500℃下的前处理，推荐用热重法来确定硫酸化氧化锆产率。应检查随硫酸根离子分解而降低的重量温度。

A recommended preparation procedure and applying method for some catalytic reactions were proposed based on the results of this investigation.As the starting material for catalyst preparation, JRC-ZRO-2 and-5 supplied by Catalysis Society of Japan are recommended. Zirconia gel should be well dried before sulfation at 300 ℃ or below.Two preparation methods of equilibrium adsorption method and ammonium sulfate kneading method had been investigated. The zirconia gel was sulfated with high reproducibility in both procedure. The sulfated zirconia with high surface area and high sulfate content was obtained when the non crystallized gel was used. The reproducibility of sulfate content on the surface was high in the ammonium sulfate kneading method. However, there was a tendency that unnecessary sulfate ions, which did not relate to the formation of active sites, remained on the surface. The recommended calcinations temperature is 650 ℃. From the reason of temperature distribution in a furnace, the calcinations at 600 ℃ is strongly recommended.The sulfated zirconia can be kept without care because this was calcined at high temperature. This can be applied for several reactions without pretreatment. It is desirable to remove adsorbed water by heating before use. The pretreatment at 500 ℃ is avoided because the decrease of acid amount was observed in some cases.Thermogravimetry is recommended as the method to confirm the sulfated zirconia production. The temperature of weight decrease accompanying the decomposition of sulfated ions should be checked.