One-step fabrication of hollow aluminosilicate microspheres with a composite zeolite/glass crystalline shell

作者：Vereshchagina Tatiana A^*; Vereshchagin Sergei N; Shishkina Nina N; Mikhaylova Olga A; Solovyov Leonid A; Anshits Alexander G

来源：Microporous and Mesoporous Materials, 2013, 169: 207-211.

DOI：10.1016/j.micromeso.2012.11.010

• Cenosphere
• Hollow zeolite microsphere
• NaA, NaX
• Mullite

One-step procedure to fabricate hollow aluminosilicate microspheres with a composite NaA(NaX)/glass/mullite composite shell was demonstrated by the direct conversion of low-silica cenospheres (Si/Al = 1.8) separated from coal fly ash. The reported method does not involve seeding and structure-directing reagents. Composition of cenospheres and the stirring of reactants at the optimal synthesis temperature (T=80 degrees C) and alkaline molarity (2.5 M NaOH) are parameters affected the formation of a monozeolitic phase (NaA or NaX). The influence of the silica-alumina composition of cenospheres on the type of zeolite phase formation is only revealed under stirring conditions. In the case of the low-silica cenospheres, NaA (LTA) zeolite crystallizes as a dominant phase (43 wt.%) (Si/Al = 1.8) under stirring of reactants, while the static conditions favor formation of the NaX (FAU) zeolite phase (45 wt.%).

• 出版日期2013-3-15