Abstract: Al-YNU-1 molecular sieve was synthesized through the post-synthesis method from highly acid-treated Fe-YNU-1 in the presence of piperidine. The effects of silica sources, structure-directing agents, composition of raw materials, and crystallization conditions on the structure and Al content of Al-YNU-1 were investigated. Optimizing the Al and H₂O amounts in the synthesis mixture, as well as the crystallization time and the acid treatment conditions applied to the as-synthesized lamellar precursors, produced a large increase in the content of Al in the Al-YNU-1 framework, to nearly double that of a sample prepared using deborated MWW as the silica source. To form Al-YNU-1, it is essential to remove most of the template molecules and framework Al species from the lamellar Al-MWW precursor by acid treatment, and to have a large number of defect sites within the Si source.

Key words: Al-YNU-1, Hydrothermal synthesis, Acid treatment, Formation mechanism, Fe-YNU-1