Journal of Chemical Technology and Biotechnology, Vol.89, No.3, 419-424, 2014
Solvothermal conversion of magadiite into zeolite omega in a glycerol-water system
BACKGROUNDZeolite omega is used as a catalyst in various fields. Expensive tetramethylammonium cations are the conventional structure-directing agents for the synthesis of zeolite omega. In this work, glycerol was used as both solvent and structure-directing agent instead of expensive quaternary ammonium compounds. Zeolite omega has been obtained through conversion of magadiite in this glycerol-water system. The effects of various parameters such as reaction time, temperature, alkalinity and glycerol content were discussed. RESULTSPure zeolite omega could be obtained at 120 degrees C for 10 days with the reactants molar composition of 14 SiO2: Al2O3: 10 Na2O: 169 H2O: 200 glycerol. Water content plays an important role in the solvothermal conversion of magadiite to zeolite omega. CONCLUSIONThe zeolite omega obtained from this system is a rather pure phase free from impurities. A preferential location of the Al atoms in the six-membered rings of the gmelinites in zeolite omega was observed. A method including extraction and calcination was introduced to remove organic species by which highly ordered pore structure of zeolite was well retained. The present work develops a novel synthesis method for zeolite omega. (c) 2013 Society of Chemical Industry