OSDA-free synthesis of zeolite beta by magadiite hydrothermal conversion method and an insight into the changes of medium-range structure during crystallization

Seed-Assisted Synthesis of Zeolite Beta from Solid-State Conversion of Magadiite and an Investigation on the Crystallization Mechanism

“…On the increasing reaction time, a significant shift from 618 to 609 cm –1 could be observed in IR spectra (Figure A­(a)–(e)). According to our previous report about the synthesis of zeolite beta in the hydrothermal condition, the signal appearing at 609 cm –1 could be interpreted as 6Rs vibration in the beta framework. So, this observation described above could unveil that preserved 6Rs units were transformed into the framework of zeolite beta little by little.…”

“…Unlike a remarkable shift of the peak corresponding to 6Rs, it was difficult to observe detailed changes of 5Rs from the IR spectra, although 5Rs in the system remain unchanged. Interestingly, in the basic composite building units of beta zeolite: bea cage, mor cage, and mtw cage, 5R was always associated with 4R, so the detailed change of 5Rs was investigated by calculating the ratio of band intensities at 572 and 524 cm −1 as we described in our previous report, 25 and the final result is presented in Figure 8B. The ratios decreased gradually and finally reached about 2, which was consistent with the primary structure units of the beta framework proposed in the literature.…”

“…We synthesized zeolite beta via the hydrothermal transformation of magadiite at 125 °C for 48 h in an OSDA-free, seed-assisted way and discussed the crystallization mechanism with the characterization and analysis of vibration spectroscopy and solid-state NMR. 25 In this work, we use a combination of magadiite conversion and solid-state, seed-assisted synthesis approach to show a rapid and novel solvent-free route for synthesizing zeolite beta by grinding and heating solid raw materials. The conversion process was described by powder X-ray diffraction, vibrational spectroscopy, solid-state 27 Al and 29 Si MAS NMR, and election microscopy in detail.…”

“…Additionally, an OSDA-free synthesis of zeolite beta via the conversion of magadiite was carried out and we investigated the crystallization mechanism in detail. We synthesized zeolite beta via the hydrothermal transformation of magadiite at 125 °C for 48 h in an OSDA-free, seed-assisted way and discussed the crystallization mechanism with the characterization and analysis of vibration spectroscopy and solid-state NMR …”

Superior Thermostability of Poly-Silicic Acid Analogues of Zeolite Composite/Secondary Building Units: A Theoretical Investigation

“…that are less stable in the reaction conditions possible. , Interzeolite conversion of BEA to MFI and FAU to CHA, STF, MTW sharing mor and d 6 r CBUs were reported. − Meng et al also realized the green synthesis of zeolites BEA, MFI, MAZ, etc. by interzeolite conversion from low-cost layered aluminum silicate minerals, such as magadiite, kenyaite, diatomite, imvite, etc. ,− These reports evidenced the significant roles of shared S/CBUs in interzeolite conversion, but the detailed mechanisms have not been fully addressed yet. , …”