Combinations of TiO2 photocatalysts and various adsorbents have been widely studied for the adsorption and photocatalytic decomposition of gaseous pollutants such as volatile organic compounds (VOCs). Herein, a TiO2-zeolite-porous glass composite was prepared using melt-quenching and partial sintering, hydrothermal treatment, and drop coating for preparation of the porous glass support and X-ze...

Abstraet--Zeolites having the structures of phillipsite, merlinoite, and gobbinsite were synthesized from clear solutions at 80~ in the system Na20-K20-Ai203-SiO2-H20 and their morphologies, cell parameters, and compositions determined. At 3.5 M silica concentration, the formation of merlinoite (synthetic zeolite W) is favored over the formation of phillipsite (synthetic zeolite ZK-19) by solut...

Zeolite-based catalyst bodies are commonly employed in a range of important industrial processes. Depending on the binder and shaping method chosen, vast differences in the reactivity, selectivity and stability are obtained. Here, three highly complementary micro-spectroscopic techniques were employed to study zeolite ZSM-5-binder interactions in SiO2-, Al2O3-, SiO2 : Al2O3- (2 : 1 mix) and kao...

Zeolite NaA nanocrystals with a narrow particle size distribution were prepared by template-free hydrothermal synthesis in thermo-reversible methylcellulose gels. The effects of the amount of methylcellulose, crystallization time and hydrothermal treatment temperature on the crystallinity and particle size distribution of the zeolite NaA nanocrystals were investigated. We found that the thermog...

Quantum cluster and embedded cluster approaches were used to investigate the proton transfer reaction for a series of model clusters of zeolite/(H2O)n ; n = 1, 2, 3, and 4, using the B3LYP/6-31G (d,p) level of theory. For both calculations, without promoted water, the hydrogen-bonded dimer of the zeolite/water system exists as a simple hydrogen-bonded complex, ZOH(H2O)2, and no proton transfer ...

This research evaluated the importance of the adsorption properties of chitosan a chitosan/zeolite conjugate film for the removal of Cr(VI) ions from solutions in the 5-260 mg/L concentration range, when the pH was adjusted to 4.0 and 6.0. The uptake capacities of the films formed by chitosan and by the chitosan/zeolite conjugate were calculated by mass balance. The equilibrium isotherms were f...

Zeolites are crystalline microporous materials with well-defined and uniform pore structure that find extensive industrial uses as adsorbents, catalysts and ion exchangers [1-2]. Zeolite films supported on different materials have been successfully prepared and have potential applications as highly selective membrane separators, membrane reactors, chemical sensor and microdevices [3-10]. Most o...

The influence of framework substituents (Al3+, Ga3+, Fe3+ and B3+) and morphology (bulk vs. nanometer-sized sheets) of MFI zeolites on the acidity and catalytic performance in the methanol-to-hydrocarbons (MTH) reaction was investigated. The Brønsted acid density and strength decreased in the order Al(OH)Si>Ga(OH)Si>Fe(OH)Si≫B(OH)Si. Pyridine 15N NMR spectra confirmed the differences in the Brø...

We describe a simple and highly efficient procedure for the single-step preparation of isatins from the commercially available anilines using H-β zeolite as a truly heterogeneous catalyst. H-β zeolite is readily separated from reaction mixture by simple filtration and reused several times without considerable loss of activity.

A novel synthetic route is designed, employing both high temperature and a nontoxic organic structure-directing agent (SDA), for the synthesis of high silica zeolite Y. The N-methylpyridinium used as an organic SDA is stable during the synthesis, and the high silica zeolite Y shows high hydrothermal stability and good catalytic performance, as well as excellent adsorptive properties.