Silicalite-1 is a silica with a zeolitic MFI (Mobil Five) structure devoid of noticeable catalytically active (, acid) sites. In this study, we present its modification with NHF solutions of varying concentrations (0.5-3 M), which generates efficient and selective acid sites for the acetalization of glycerol with acetone towards solketal (2,2-dimethyl-1,3-dioxolane-4-methanol).
View Article and Find Full Text PDFThe ethanol dehydration process is studied regarding protonic and Ag-loaded chabazite zeolite in advanced FT-IR and UV-vis spectroscopic studies with simultaneous mass spectroscopy and gas chromatography analyses of products. The spectroscopic investigation provides information on the species formed on the surface of catalysts, while mass spectrometry and gas chromatography methods identify the desorbed products. These studies are also supported by spectroscopic, chromatographic, and thermogravimetric analyses of coke species formed over the catalyst's surface during ethanol conversion.
View Article and Find Full Text PDFThe outcome of the demetalation process of zeolites depends on applied treatment conditions and can lead to the formation of either open or constrained mesopores. The quaternary ammonium cations as pore-directing agents during desilication are responsible for developing constrained mesoporosity with bottleneck entrances. However, higher mesopore surface area and higher accessibility of acid sites are often found for the hierarchical zeolites with constrained mesopores.
View Article and Find Full Text PDFCovalent triazine-based frameworks have attracted much interest recently due to their high surface area and excellent thermal and electrochemical stabilities. This study shows that covalently immobilizing triazine-based structures on spherical carbon nanostructures results in the organization of micro- and mesopores in a three-dimensional manner. We selected the nitrile-functionalized pyrrolo[3,2-b]pyrrole unit to form triazine rings to construct a covalent organic framework.
View Article and Find Full Text PDFIntentionally introduced defects into solid materials create opportunities to control and tune their diverse physicochemical properties. Despite the growing interest in defect-engineered metal-organic frameworks (MOFs), there are still only a handful of studies on defective proton-conducting MOFs, including no reports on two-dimensional ones. Ion-conducting materials are fundamentally of great importance to the development of energy storage and conversion devices, including fuel cells and batteries.
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