Control of process for synthesis of ZSM-35 zeolite by in-situsolid phase transformation method

Using ethylenediamine(EDA) as template agent,ZSM-35 zeolite was prepared by in-situ solid phase transformation method.The influences on crystallization process as well as crystallization mechanism were investigated in detail by XRD method.Results showed that the proper silicon-aluminum molar ratio n(SiO2)/n(Al2O3) for synthesis of ZSM-35 zeolite is 21～37;both Na+ and EDA play a cooperative structure-orientation role in the synthesis of ZSM-35 zeolite;suitable time for crystallization is 14～21 h,while extension of crystallization time tends to change ZSM-35 zeolite into ZSM-5 zeolite.Results of study on crystallization mechanism indicated that the synthesis process displays features of solid phase crystallization mechanism.Since both ZSM-35 zeolite and ZSM-5 zeolite have same secondary structural units,they are easily to transform each other in the crystallization process.