Fecha de publicación: 21/11/2024 Fuente: Molecules - Revista científica (MDPI) Molecules, Vol. 29, Pages 5512: Generation of Acid Sites in Nanostructured KIT-6 Using Different Methods to Obtain Efficient Acidic Catalysts for Glycerol Acetalization to Solketal
Molecules doi: 10.3390/molecules29235512
Authors:
Ewa Janiszewska
Jolanta Kowalska-Kuś
Justyna Wiktorowska
Aldona Jankowska
Agata Tabero
Agnieszka Held
Stanisław Kowalak

This study explored the preparation of pure silica KIT-6, as well as KIT-6 materials with an enhanced concentration of surface OH groups through aluminum incorporation or NH4F treatment. These materials with various contents of surface OH groups were subsequently modified via the post-synthesis grafting of sulfonic groups using 3-mercaptopropyltrimethoxysilane as a precursor, followed by oxidation to introduce acidic sites. The catalysts were thoroughly characterized using XRD, nitrogen adsorption/desorption, SEM-EDS, TEM, and FT-IR techniques to confirm their structural and chemical properties. The catalytic activity of acid-functionalized mesoporous silicas of the KIT-6 structure was further evaluated in the acetalization of glycerol to produce solketal. The results demonstrated a significant influence of the surface OH group concentration and acidic site density on catalytic performance, with KIT-6_F_SO3H showing the highest efficiency in glycerol-to-solketal conversion. This study provides valuable insights into the design of efficient catalytic systems for the valorization of biodiesel-derived glycerol into high-value chemicals, offering a sustainable approach to waste glycerol utilization.