ICGM, University Montpellier, CNRS, ENSCM, 34095 Montpellier, France.
Department of Chemistry, College of Science, University of Kerbala, Karbala 56001, Iraq.
Molecules. 2022 Apr 14;27(8):2534. doi: 10.3390/molecules27082534.
The development of green and sustainable materials for use as heterogeneous catalysts is a growing area of research in chemistry. In this paper, mesoporous SiO-AlO mixed oxide catalysts with different Si/Al ratios were prepared via hydrolytic (HSG) and nonhydrolytic sol-gel (NHSG) processes. The HSG route was explored in acidic and basic media, while NHSG was investigated in the presence of diisopropylether as an oxygen donor. The obtained materials were characterized using EDX, N-physisorption, powder XRD, Si, Al MAS-NMR, and NH-TPD. This approach offered good control of composition and the Si/Al ratio was found to influence both the texture and the acidity of the mesoporous materials. According to Al and Si MAS NMR analyses, silicon and aluminum were more regularly distributed in NHSG samples that were also more acidic. Silica-alumina catalysts prepared via NHSG were more active in esterification of acetic acid with n-BuOH.
将绿色和可持续材料开发为多相催化剂是化学领域中一个不断发展的研究领域。本文通过水解（HSG）和非水解溶胶-凝胶（NHSG）工艺制备了具有不同 Si/Al 比的介孔 SiO-AlO 混合氧化物催化剂。HSG 路线在酸性和碱性介质中进行了探索，而 NHSG 则在作为氧供体的二异丙醚存在下进行了研究。采用 EDX、N-物理吸附、粉末 XRD、Si、Al MAS-NMR 和 NH-TPD 对所得材料进行了表征。该方法可很好地控制组成，并且 Si/Al 比影响介孔材料的结构和酸度。根据 Al 和 Si MAS NMR 分析，硅和铝在 NHSG 样品中分布更均匀，并且 NHSG 样品也更具酸性。通过 NHSG 制备的硅铝催化剂在乙酸与正丁醇的酯化反应中更具活性。
