University of Osnabrück, Institute of Chemistry of New Materials, Physical Chemistry, Barbarastraße 7, 49069 Osnabrück, Germany.
Chem Asian J. 2013 Sep;8(9):2211-9. doi: 10.1002/asia.201300488. Epub 2013 Jun 25.
This contribution aims at evaluating different synthesis procedures leading to zirconia-based aerogels. A series of undoped and yttrium-doped zirconia aerogels have been prepared via hydrolysis and condensation reaction of different alkoxy- and different inorganic salt-based precursors followed by supercritical drying. Well-established but deleterious zirconium n-propoxide (TPOZ) or zirconium n-butoxide (TBOZ) were used as metal precursors in combination with acids like nitric acid and acetic acid as auxiliary agent for the generation of non-yttrium stabilized zirconia aerogels. Yttrium-stabilized zirconia aerogels as well as pure zirconia aerogels were obtained by the salt route starting from ZrCl4 and crosslinking agents like propylene oxide or acetylacetone. The characteristics of the products were analyzed by nitrogen adsorption measurements, electron microscopy, and X-ray scattering. It turned out that with respect to all relevant properties of the aerogels as well as the practicability of the synthesis procedures, approaches based on inexpensive non-toxic salt precursors are the methods of choice. The salt-based approaches allow not only for low-cost, easy-to-handle synthesis procedures with realizable gelation times of less than 60 seconds, but also delivered the products with the highest surface area (449 m(2) g(-1) for ZrCl4) within this series of syntheses.
本研究旨在评估不同的合成工艺制备二氧化锆基气凝胶。通过不同烷氧基和无机盐前体的水解和缩合反应，然后进行超临界干燥，制备了一系列未掺杂和钇掺杂的二氧化锆气凝胶。采用正丙氧基锆（TPOZ）或正丁氧基锆（TBOZ）作为金属前体，与硝酸和乙酸等酸结合作为非钇稳定二氧化锆气凝胶生成的辅助剂。通过从 ZrCl4 和交联剂如环氧丙烷或乙酰丙酮出发的盐路线，制备了钇稳定氧化锆气凝胶和纯氧化锆气凝胶。通过氮气吸附测量、电子显微镜和 X 射线散射分析了产物的特性。结果表明，对于气凝胶的所有相关性质以及合成工艺的实用性而言，基于廉价无毒盐前体的方法是首选方法。基于盐的方法不仅允许进行低成本、易于处理的合成工艺，凝胶时间可短至 60 秒，而且还可以在该系列合成中获得具有最高表面积（449 m2/g 用于 ZrCl4）的产物。
