In situ monitoring of hydrothermal and solvothermal synthesis of molecular sieves

点击翻译按钮获取中文摘要

Porous materials, esp. zeolites and metal-organic frameworks (MOF), play a key role in chemical industry as catalysts and adsorbents. The joined project aims at the development of novel spectroscopic techniques applied in a specific combination with already known techniques for a direct comparative and complementary in situ monitoring of the hydrothermal and solvothermal synthesis of zeolites and metal-organic frameworks (MOF), respectively. This will open new perspectives for improving the scientific understanding for the robust preparation of both of these material classes and for their predictable tuning of required properties. The combined use of in situ NMR, Raman, FTIR spectroscopy, along with XRD, ultrasonic spectroscopy, and dynamic light scattering will allow to study the crystal formation processes at atomic-, molecular-, nano- and micrometric levels at the same and real time mode in a time-resolved way. Such specifically combined investigation will give rise to obtain fundamentally new information about the processes at the different stages of molecular sieve formation namely (i) molecular interaction (NMR, Raman, FTIR); (ii) the formation of crystallization nuclei (NMR, Raman, FTIR) and (iii) the crystal growth (US spectroscopy, DLS, XRD).Specific goals of the project include: 1) Elaboration of hydrothermal and solvothermal synthetic procedures adapted to the in situ studies of zeolites BEA and MFI as well as MIL-53-based MOFs for combined application of various in situ techniques; 2) Development and optimization of in situ cells and methodological approaches for the in situ monitoring of hydrothermal and solvothermal synthesis at the atomic, molecular, nano- and micrometric scales using MAS NMR; FTIR, Raman, DLS and US spectroscopic techniques; 3) Elucidation of the effect of the main parameters of hydrothermal synthesis, namely, the method of synthesis (clear solution process, sol-gel synthesis, dry-gel conversion), type of template, type of mineralizing agent and type of heteroatom on the mechanism of zeolites BEA and MFI formation; 4) Unravel the effect of the main parameters of solvothermal synthesis of MOFs, namely, type and amount of solvent, temperature and metal source/ linker ratio on the mechanism of MIL-53 formation.