Sulfate-promoted Titania and Zirconia Aerogels as Solid Superacids

制备了钛酸锂和氧化锆气凝胶，并对其作为硫酸盐超强酸载体进行了评价。气凝胶的合成采用溶胶-凝胶法和超临界铺层相结合的方法。通过氮气吸附、X射线衍射和差热分析，研究了这些材料在添加和不添加硫酸盐离子的热处理条件下的稳定性和结晶行为。用Hammett指示剂、吸附吡啶的热重和红外测量以及异丁烷的反应来表征硫酸盐促进的气凝胶的酸性质。超强酸(比水中的酸更强的酸)对几个行业的许多操作都是必不可少的。有许多液体和气态超强酸可用，但它们总是存在严重的职业或环境危害。固体超强酸更容易控制和控制，开发固体超强酸是争取更安全的工业环境的主要目标。//

Aerogels of litania and zirconia are prepared and evaluated as supports for sulfate-ion superacids. The aerogels are synthesized using a sol-gel process in conjunction with supercritical laying. The stability and crystallization behavior of these materials in response to heat treatments, both with and without the addition of sulfate ions, are studied by nitrogen adsorption, X-ray diffraction, and differential thermal analysis. Acid properties of sulfate- promoted aerogels are characterized with Hammett indicators, thermogravimeteric and infrared measurements of adsorbed pyridine, and the reaction of isobutane. Superacids (acids stronger than what can be obtained in water) are essential to many operations in several industries. A number of liquid and gaseous superacids are available, but they invariably present serious occupational or environmental hazards. Solid superacids are much easier to control and contain and their development is a major objectives in the striving for a safer industrial environment. //