Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Nat Chem. 2009 Jun;1(3):217-24. doi: 10.1038/nchem.208. Epub 2009 May 17.
Aerogels are low-density porous materials, made mostly of air, for which hundreds of applications have been found in recent years. Inorganic oxide-based aerogels have been known for a long time, carbon aerogels were discovered in the early 1990s and sulfur- and selenium-based aerogels (chalcogels) are the most recent additions to this family. Here we present new aerogels made of Co(Ni)-Mo(W)-S networks with extremely large surface areas and porosity. These systems are formed by the coordinative reactions of (MoS(4))(2-) and (WS(4))(2-) with Co(2+) and Ni(2+) salts in non-aqueous solvents. We show that these low-density sponge-like networks can absorb conjugated organic molecules and mercury ions, and preferentially adsorb CO(2) over H(2), which illustrates their high potential as gas-separation media. The chalcogels are shown to be twice as active as the conventional sulfided Co-Mo/Al(2)O(3) catalyst for the hydrodesulfurization of thiophene.
气凝胶是一种低密度多孔材料,主要由空气组成,近年来已发现数百种应用。无机氧化物基气凝胶早已为人所知,碳气凝胶则是在 20 世纪 90 年代初发现的,而硫基和硒基气凝胶(硫属气凝胶)是该家族中最新的成员。在这里,我们展示了由 Co(Ni)-Mo(W)-S 网络组成的具有极高表面积和孔隙率的新型气凝胶。这些体系是由(MoS(4))(2-)和(WS(4))(2-)与 Co(2+)和 Ni(2+)盐在非水溶剂中的配位反应形成的。我们表明,这些低密度海绵状网络可以吸收共轭有机分子和汞离子,并优先吸附 CO(2)而不是 H(2),这说明了它们作为气体分离介质的高潜力。与传统的硫化 Co-Mo/Al(2)O(3)催化剂相比,硫属气凝胶对噻吩的加氢脱硫反应的活性要高两倍。