Interpretation of catalytic performance during the MTH process is hampered by heat transport phenomena. We demonstrate that large temperature rises can occur during fixed bed labscale catalyst testing of ZSM-5, even when a large catalyst bed dilution is applied. Formation of mesopores in ZSM-5 leads to partial mitigation of these effects because of a lower generation of heat per unit catalyst v...

Microspectroscopic methods were explored to investigate binder effects occurring in ZSM-5-containing SiO2- and Al2O3-bound millimetre-sized extrudates. Using thiophene as a selective probe for Brønsted acidity, coupled with time-resolved in situ UV/Vis and confocal fluorescence microspectroscopy, variations in reactivity and selectivity between the two distinct binder types were established. It...

The influence of a highly oxygenated, polar protic reaction medium, that is, levulinic acid in 2-ethylhexanoic acid, on the dealumination of two zeolite-supported ruthenium catalysts, namely Ru/H-β and Ru/H-ZSM-5, has been investigated by 27 Al triple-quantum magic-angle spinning nuclear magnetic resonance spectroscopy (3QMAS NMR). Upon use of these catalysts in the hydrogenation of levulinic a...

The adsorption and desorption of N2O on main-group ion-exchanged ZSM-5 was studied using temperature-programmed desorption (TPD) and density functional theory (DFT) calculations. TPD experiments were carried out to determine the desorbed temperature Tmax corresponding to the maximum mass intensity of N2O desorption peak and adsorption capacity of N2O on metal-ion-exchanged ZSM-5s. The results i...

A new catalyst comprising cerium and silver ion-exchanged ZSM-5 zeolite is reported in this paper, for the reduction of nitric oxide by methane in the presence of excess oxygen. The bi-cation exchanged Ce-Ag-ZSM-5 catalyst was very active for this reaction, while either Ce-ZSM-5 or Ag-ZSM-5 alone showed low activity. The presence of oxygen in the feed gas mixture enhanced the activity of the ca...

Structured filamentous zeolitic materials were synthesized by ZSM-5 coatings deposited on the glass fibrous supports. A homogeneous coverage of the support filaments was obtained via the synthesis of MFI crystals in fluoride-containing media at neutral pH ∼7. These materials combine the open macrostructure of woven filamentous fabrics with well-defined microstructure of ZSM-5 crystals. The samp...

ZSM-5 zeolites were prepared at neutral pH by fluoride-mediated synthesis. The degree of crystallinity, the specific surface area and the crystal size are higher than those of the zeolites prepared under alkaline conditions. Moreover, by varying the F/Si ratio from 0.3 to 1.6, the H–[F]–ZSM-5 zeolites with crystal size ranging from 10 to 75 lm and the specific surface areas from 60 up to 350 m/...

The direct conversion of methane and carbon dioxide to acetic acid is one of the most challenging research topics. Using the density functional theory (M06-L) the study reveals the catalytic activity of the Au(I)-ZSM-5 zeolite in this reaction. The Au(I)-ZSM-5 is represented by a 34T quantum cluster model. The activation of the C-H bond over the Au-ZSM-5 zeolite would readily take place via the...

The mono(μ-oxo) dicopper cores present in the pores of Cu-ZSM-5 are active for the partial oxidation of methane to methanol. However, copper on the external surface reduces the ratio of active, selective sites to unselective sites. More efficient catalysts are obtained by controlling the copper deposition during synthesis. Herein, the external exchange sites of ZSM-5 samples were passivated by ...