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

在此基础上，提出了一些催化反应的推荐制备工艺和应用方法。推荐日本催化学会提供的JRC-ZRO-2和jrc - zro -5作为催化剂制备的起始原料。氧化锆凝胶在300℃或更低的温度下进行硫化前应充分干燥。研究了平衡吸附法和硫酸铵揉制法两种制备方法。在这两种方法中，氧化锆凝胶硫酸酸化具有高重复性。采用非结晶凝胶法制备了高表面积、高硫酸盐含量的硫酸氧化锆。硫酸铵揉制法表面硫酸盐含量重现性高。然而，存在多余的硫酸盐离子残留在表面的趋势，这些硫酸盐离子与活性位点的形成无关。推荐的煅烧温度为650℃。由于炉内温度分布的原因，强烈建议在600℃下进行煅烧。硫酸氧化锆是在高温下煅烧而成的，因此可以放心保存。这可以应用于几个不需要预处理的反应。最好在使用前通过加热去除吸附的水。在某些情况下，由于酸量减少，可以避免500℃的预处理。推荐热重法作为确定硫酸氧化锆生产的方法。应检查随硫酸盐离子分解而产生的减重温度。

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.