Synthesis of ZSM-5 and ZSM-11 Zeolites With TBA and TBP Cations and Their Structural Characterization

Abstract

Abstract ZSM-5 and ZSM-11 zeolites were synthesized in the xNa 2 O-yTBABr(TBPBr)-Al 2 O 3 -zSiO 2 -3600 H 2 O system (10 ≤ × ≤ 20, 4 ≤ y ≤ 27, 60 ≤ z ≤ 800). When the templating agent was tetrabutylammonium cation the product was always ZSM-11. In Al-free system with tetrabutylphosphonium cation as the templating agent the product was either ZSM-5 (at the crystallization temperature 433K) or ZSM-11 (at the crystallization temperature 403K). With aluminium present in the system and TBP templating agent, the products were intergrowths of ZSM-5 and ZSM-11 at SiO 2 /Al 2 O 3 ratios higher than 90 in the starting gel. After the calcination of samples obtained with TBP templating agent, phosphorus remained in the channels of zeolite in the form of surface complex. This is substantiated by X-ray diffraction analysis, thermal analysis and FTIR analysis.