Synthesis of the Zeolites from SBU: An SSZ-13 Study

Zeolite SSZ-13 was successfully synthesized via interzeolite conversion of zeolites X, A, and ZSM-5. Si(4Al) and Si(1Si, 3Al) were monitored by Si-29 MAS NMR spectroscopy and together with the ion exchange capacity to Co(II) ions were employed to monitor secondary building units (SBU) and (SiAl)(n) sequences transferred from parent X and A zeolites to the structure of SSZ-13. The starting material serves as an Al and partial Si source and has to be disintegrated into linear or branched (SiAl) n sequences. Also, no mutual structural building units, e.g., hexagonal prisms or 6 rings, are required for the formation of SSZ-13 zeolite. Among transferred (SiAl) n sequences, a significant fraction (ca. 45%) is relocated in the form of chains with at least five T atoms containing three Al atoms (Al-TRI), decreasing the ion exchange capacity as only two of the three Al atoms are involved in balancing one Co(II).

Automated summary

Zeolite SSZ-13 was successfully synthesized by interzeolite conversion of zeolites X, A, and ZSM-5. Si-29 MAS NMR spectroscopy was used to monitor Si(4Al) and Si(1Si, 3Al) species, while the ion exchange capacity to Co(II) ions was employed to track the transfer of secondary building units (SBU) and (SiAl) sequences from parent X and A zeolites to the structure of SSZ-13. It was found that a significant fraction of transferred (SiAl) sequences formed chains with at least five T atoms containing three Al atoms, leading to a decrease in ion exchange capacity.