Seeding-free synthesis of oriented zeolite LTA membrane on PDI-modified support for dehydration of alcohols

ABSTRACT

A seeding-free synthesis method is developed for preparation of oriented zeolite LTA membranes by using 1,4-phenylene diisocyanate (PDI) as a molecular linker. Before hydrothermal synthesis, –NCO groups are introduced with the functionalization of Al₂O₃ supports by PDI. A thin, well intergrown zeolite LTA membrane with a thickness of about 4.0 µm can be formed on the PDI-modified Al₂O₃ supports. The zeolite LTA membrane displays high pervaporation performances for dehydration of alcohols. At 90°C, the separation factor of the zeolite LTA membrane is 4480 for dehydration of 95 wt% ethanol/water mixtures, with a high water flux of 3.4 kg·m⁻²·h⁻¹.

KEYWORDS:

• Molecular sieve membrane
• zeolite lta membrane
• covalent modification
• pervaporation
• dehydration of alcohols

Acknowledgments

Financial supports by National Natural Science Foundation of China (21761132003, 21576273, 21276262, 21606246), National High Technology Research and Development Program of China (2015AA03A602), K.C.Wong Education Foundation (rczx0800), Key Research Program of Frontier Sciences of CAS (QYZDB-SSW-JSC037), and Ningbo Science and Technology Innovation Team (2014B81004).