Synthesis and characterization of ZSM-5 coatings onto cordierite honeycomb supports

摘要

Zeolite ZSM-5 layers (up to ca.30% by weight) have b3en synthesized on cordierite substrates,following eithr a direct hydrothermal synthesis procedure or a secondary growth method,in this case after seeding of the support.The Si/Al ratio in the synthesis gel ranged from 14 to 100,but layers with a high Al content (i.e.a low Si/Al ratio) could not be prepared directly on the cordierite support.However,MFI layers with a low Si/Al ratio were readily grown after depositing an intermediate Si-rich layer.The results also show that the Si/Al ratio of the synthesis gel has a direct effect on the morphology,crystallinity and orientation of the MFI layer formed.