In-situ synthesis of SAPO-34 molecular sieves on monolithic cordierite substrates

SAPO-34 molecular sieves have been successfully synthesized onto the cordie rite substrates by hydrothermal technique, and characterized by XRD and SEM methods, The results show that SAPO-34 layers with the thickness about 30 mum are evenly distributed onto the inner walls of the cordierite substrate , which results in a weight increase of 15%-25% of the substrate. The molar ratio of Et3N/Al2O3 had an important effect on the nature of the molecular sieve product crystallized on the substrate. When n(Et3N)/n(Al2O3)=4. 0, p ure SAPO-34 was crystallized on the cordierite substrate; whereas when n(Et 3N)/n(Al2O3)=2, 5, a mixture product of SAPO-34 and SAPO-5 was formed on th e substrate, In order to explore the mechanism of SAPO-34 formation on the cordierite substrate, the changes of the crystallization process on the sub strate as well as in the solution has also been investigated.