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. //
