The fractal dimensions of FeZSM-5 zeolites were used to characterize the change in their geometry depending on different postsynthesis treatments. The fractal dimension values were estimated from the Dubinin–Astakhov isotherms of nitrogen adsorption and related to the activity of these zeolites in the benzene hydroxylation to phenol by nitrous oxide. The zeolites had two different iron contents...

Increasing demand for sustainable chemicals and fuels has pushed academia and industry to search for alternative feedstocks replacing crude oil in traditional refineries. As a result, an immense academic attention has focused on the valorisation of biomass (components) and derived intermediates to generate valuable platform chemicals and fuels. Zeolite catalysis plays a distinct role in many of...

Resorcinol-formaldehyde aerogels and carbon aerogels of different mesoporosities have been used as templates for preparing bimodal zeolites of mesopores. Samples were thoroughly characterized with X-ray diffraction, field emission scanning electron microscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, N(2) adsorption at 77 K, as well as FT-IR spectroscopy and (29)Si nuclear ...

The unique properties of microporous zeolites, including ion-exchange properties, adsorption, molecular sieving, catalysis, conductivity have been exploited in improving the performance of gas sensors. Zeolites have been employed as physical and chemical filters to improve the sensitivity and selectivity of gas sensors. In addition, direct interaction of gas molecules with the extraframework ca...

The encapsulation of metal clusters (Pt, Ru, Rh) within MFI was achieved by exchanging cationic metal precursors into a parent zeolite (BEA, FAU), reducing them with H2 to form metal clusters, and transforming these zeolites into daughter structures of higher framework density (MFI) under hydrothermal conditions. These transformations required MFI seeds or organic templates for FAU parent zeoli...

Heck reactions were performed with 4-bromoacetophenone and n-butyl acrylate, yielding the trans-arylated acrylate ester with high selectivity. Pd–zeolite catalysts were compared with supported Pd metal catalysts. In order to obtain an active and heterogeneous catalyst, the preformed or in situ-formed catalytically active Pd0 species and the PdII intermediates must be sufficiently stabilized on ...

The synthesis of the ZSM-5 and beta zeolites in their nanosized form has been achieved by using simple alkyl-substituted mono-cationic cyclic ammonium cations as OSDA molecules. The particular combination of a cyclic fragment and a short linear alkyl-chain group (preferentially C4) within the monocationic OSDA molecules allows directing the crystallization of nanosized zeolites with excellent s...

In this work, a systematic molecular simulation study was performed to compare the separation of CO2/N2 and CH4/N2 mixtures in two different classes of nanoporous materials, zeolites, and metal-organic frameworks (MOFs). For this purpose, three zeolites (MFI, LTA, and DDR) and seven MOFs (Cu-BTC, MIL-47 (V), IRMOF-1, IRMOF-12, IRMOF-14, IRMOF-11, and IRMOF-13) were chosen as the representatives...

DOR and MQMAS NMR techniques were applied in the high field of 17.6 T to the study of several oxygen-17 enriched zeolites with the ratio Si/Al = 1. The tendency that the isotropic chemical shift of the O NMR decreases with increasing bond angle (or s-character of the oxygen hybrid orbital) was confirmed by this study. A quite linear correlation exists for the oxygen sites in the zeolites A and ...