Liquid phase preparation, amorphous solid water

Metastable amorphous solids can in general be prepared from stable phases by bringing in excess free energy [5]. In the case of water, amorphous solids have been prepared from stable phases in all three aggregate states from the gas, the liquid, and the crystalline solid [131]. 

The fact that zeolite seed crystals can improve the mechanical strength of the synthesized discs, was reported in synthesis of zeolite ZSM-5 with vapor phase method. Zeolite ZSM-5 disc was prepared with ethylenediamine (EDA) and ammonia solution (or distilled water) as liquid phase while the mixture of amorphous aluminosilicate gel, zeolite ZSM-5 seed crystals was the solid phase. The obtained ZSM-5 discs not only have high mechanical strength (up to 3.5 X lO Pa/m ) but also high relative crystallinity. It was also found that the mechanical strength would further increase by replacing the water with ammonia solution in liquid phase. The increase of mechanical strength of zeolite seed crystal may result from the fact that seeds serve as binders to cause close assembly of small zeolite ZSM-5 particles. 

Olah et al. reported the triflic acid-catalyzed isobutene-iso-butylene alkylation, modified with trifluoroacetic acid (TFA) or water. They found that the best alkylation conditions were at an acid strength of about//q = —10.7, giving a calculated research octane number (RON) of 89.1 (TfOH/TFA) and91.3 (TfOH/HaO). Triflic acid-modified zeohtes can be used for the gas phase synthesis of methyl tert-butyl ether (MTBE), and the mechanism of activity enhancement by triflic acid modification appears to be related to the formation of extra-lattice Al rather than the direct presence of triflic acid. A thermally stable solid catalyst prepared from amorphous silica gel and triflic acid has also been reported. The obtained material was found to be an active catalyst in the alkylation of isobutylene with n-butenes to yield high-octane gasoline components. A similar study has been carried out with triflic acid-functionalized mesoporous Zr-TMS catalysts. Triflic acid-catalyzed carbonylation, direct coupling reactions, and formylation of toluene have also been reported. Tritlic acid also promotes transalkylation and adaman-tylation of arenes in ionic liquids. Triflic acid-mediated reactions of methylenecyclopropanes with nitriles have also been investigated to provide [3 + 2] cycloaddition products as well as Ritter products. Tritlic acid also catalyzes cyclization of unsaturated alcohols to cyclic ethers. ... 

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