A Multi-Nuclear MAS-NMR Study on the Structural Properties of Silicalite-1 Zeolite Synthesized Using N- and P-Based Organic Structure Directing Agents

The nature of organic structure directing agents (OSDAs) is paramount importance in the final properties zeolites, particularly framework and porosity. Recently, use P-containing OSDAs has been employed for new but there little discussion compared to their analogues N-OSDAs. main objective this work characterization pure silica MFI zeolite (silicalite-1) prepared by dual-template route with tetrapropylammonium (TPA), tetrapropylphosphonium (TPP) cations, mixtures thereof aiming understand advanced NMR methods how influences physico-chemical zeolite. Silicalite-1 successfully synthesized using procedure TPA TPP molecules. Both are incorporated into without any specific preference, differently that observed before TEA/TEP system, homogenously mixed inside voids. presence leads incorporation less F, raising concentration Q3-defective sites silicalite-1 zeolites. Detailed results indicate those structural defects close –CH3 group entrapped these consist at least two silanol groups stabilizing Si-O- species, which responsible charge balancing.