Influence of Reaction Conditions on the Crystal Size and Yield in Hydrothermal Synthesis of ZSM-5 Molecular Sieve Zeolites

摘要

Nanocrystalline ZSM-5 can be used as catalysts or catalyst supports, and it has higher catalytic efficiency compared with micro-sized ZSM-5 zeolite because of its large specific surface area, so it attracted wide attention. This paper mainly discusses the hydrothermal synthesis of nanocrystalline ZSM-5. Aluminium nitrate, tetrapropyl ammonium hydroxide (TPAOH) and tetraethyl orthosilicate (TEOS) are used as main reactants and reaction conditions are studied such as Si/Al, dispersion medium (water, ethanol and butanol), reaction temperature and reaction time so as to probe how they affect the size and yield of product. The best reaction conditions are confirmed by experiments and ZSM-5 zeolite has a average size of 60nm and yield over 90% prepared with ethanol as dispersion medium at 100°C for 48 hours. This study lays foundation for next-step preparation of the catalyst.