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.

in this research, zeolite-tio2 nanocomposite was prepared for degradation of dibenzothiophene as a typical aromatic organosulfur compound of transportation fuels.the synthesized tio2 was immobilized on the surface of clinoptilolite by solid state dispersion (ssd) method. the nanocomposite was then characterized by xrd, ftir, tem and sem techniques. photodegradation of dibenzothiophene in n-hexa...

Density functional theory (DFT) calculations have been used to investigate the oxidative carbonylation of methanol on Pd(II)/β zeolite. Activation energies for all the elementary steps involved in the commonly accepted mechanism, including the formation of dimethyl carbonate, methyl formate and dimethoxymethane, are presented. Upon conducting the calculations, we identify that the Pd(2+) cation...

A two-step procedure for the post-synthetic preparation of Lewis acidic Sn-, Zr- and Ti-zeolite β is reported. Dealumination of a commercially available Al-β zeolite leads to the formation of highly siliceous material containing silanol nests, which can be filled in a second step via the solid-state ion-exchange or impregnation of an appropriate metal precursor. Spectroscopic studies indicate t...

Different from a bulk phase, a gas nanophase can have a significant effect on liquid motion. Herein we report a series of experimental results on molecular behaviors of water in a zeolite β of molecular-sized nanopores. If sufficient time is provided, the confined water molecules can be "locked" inside a nanopore; otherwise, gas nanophase provides a driving force for water "outflow". This is du...

Development of highly active heterogeneous catalysts is an effective strategy for modern organic synthesis chemistry. In this work, acidic mesoporous zeolite ZSM-5 (HZSM-5-M), acidic-free mesoporous zeolite TS-1 (TS-1-M), and basic ETS-10 zeolite supported metal Cu catalysts were prepared to investigate their catalytic performances in the hydroxysulfurization of styrenes with diaryl disulfides....

Gas-phase dehydration of lactic acid (LA) to acrylic acid (AA) was investigated over alkali-exchanged β zeolite (M(x)Na(1-x)β, M=Li(+), K(+), Rb(+), or Cs(+)) of different exchange degrees (x). The reaction was conducted under varying conditions to understand the catalyst selectivity for AA production and trends of byproduct formation. The nature and exchange degree of M(+) were found to be cri...

In this research, zeolite-TiO2 nanocomposite was prepared for degradation of dibenzothiophene as a typical aromatic organosulfur compound of transportation fuels.The synthesized TiO2 was immobilized on the surface of clinoptilolite by Solid State Dispersion (SSD) method. The nanocomposite was then characterized by XRD, FTIR, TEM and SEM techniques. Photodegradation of ...

Benzene alkylation with propylene was studied in the gas phase using a catalytic membrane reactor and a fixed-bed reactor in the temperature range of 200-300 °C and with a weight hourly space velocity (WHSV) of 51 h-1. β-zeolite was prepared by hydrothermal synthesis using silica, aluminum metal and TEAOH as precursors. The membrane's XRD patterns showed good crystallinity for the β-zeolite fil...

The mechanism of self-assembly induced by H2O molecules is studied for layered saponite nanoparticles and zeolite with the cage structure by means of positronium (Ps) annihilation spectroscopy together with thermogravimetry and differential thermal analysis (TG-DTA). Prior to hydration the saponite exhibits two kinds of open spaces with their sizes of ∼3 Å and ∼9 Å, whereas open spaces with the...