• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.134-134
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• 2003

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.138.1-138
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• 2002

• Proceedings of the Korean Ceranic Society Conference
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• 2003.04a
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• pp.166.2-166
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• 2003

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.142-146
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• 2008

Titanium silicalite-1 catalyst was prepared using a $SiO_2-TiO_2$ xerogel and applied to allylchloride (ALC) epoxidation by $H_2O_2$ as oxidant in a batch reactor. The reaction temperature was varied from 25 to $55^{\circ}C$, and the concentrations of ALC and $H_2O_2$ were changed from 0.2 to 3 M and from 0.2 to 1.5 M, respectively. The kinetic data obtained were applied to the power rate law, Eley-Rideal, and a Langmuir-Hinshelwood model, and power rate law fits the experimental data best. Activation energy was 27.9 kJ/mol, and the reaction orders with respect to $H_2O_2$ and ALC were determined to be 0.41 and 0.52, respectively.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.634-638
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• 2004

Titanium silicalite-1 (TS-1) molecular sieve was produced by microwave heating of amorphous titanium-containing solid precursors after impregnation with aqueous TPAOH solution. $SiO_2-TiO_2$ xerogel, sub-micron sized $SiO_2-TiO_2$ prepared by thermal plasma process, and Ti-containing mesoporous silica, Ti-HMS, were tested as the solid phase substrates. Highly crystalline product was obtained within 30 min. after microwave irradiation with yields over 90% using $SiO_2-TiO_2$ xerogel, which showed essentially identical physicochemical properties to TS-1 prepared by conventional hydrothermal method. Excellent catalytic activity was also obtained for 1-hexene epoxidation using $H_2O_2.\;SiO_2-TiO_2$ particles prepared by thermal plasma and Ti-HMS were found inferior as a substrate for TS-1, probably due to difficulties in wetting the surface uniformly with TPAOH.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.11 no.1
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• pp.53-58
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• 2005

Titanoalumino silicalite (TAS) was prepared hydrothermally, and the effects of synthesis parameters such as silica/alumina sources, $SiO_2/TiO_2$ ratio, and aging treatment were investigated. The structure, crystal size, and shape were examined by XRD and SEM, and the extent of titanium incorporation into the zeolite framework was examined using UV-vis DRS spectroscopy. For TAS preparation, aging of ca. 24h was essential, and the faster crystallization rates were achieved with Cab-O-Sil than with Ludox or TEOS as a silica source. In addition, the higher crystallinity and faster crystallization rate were obtained using sodium aluminate as an aluminum source.

• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.140-142
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• 2002

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.639-647
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• 1998

Al-containing titanium silicalite-1 ([Al]-TS-1) catalyst was prepared hydrothermally, and the effects of synthesis parameters such as silica/alumina sources, $SiO_2/TiO_2$ ratio, and aging treatment were investigated. The structure, crystal size, and shape were examined by XRD and SEM, and the extent of titanium incorporation into the zeolite framework was examined using UV-vis DRS spectroscopy. For [Al]-TS-1 catalyst preparation, aging of ca. 24h was essential, and the faster crystallization rates were achieved with Cab-O-Sil than with Ludox or TEOS as a silica source. In addition, the higher crystallinity and faster crystallization rate were obtained using sodium aluminate as an aluminum source. 2-butanol oxidation using $H_2O_2$ as an oxidant was carried out to confirm the redox property of the [Al]-TS-1. Acid sites catalyzed toluene alkylation study indicated that lattice titanium species in [Al]-TS-1 weakened the acid strength, and the para-ethyltoluene selectivity was enhanced as a results.

• Korean Journal of Materials Research
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• v.26 no.3
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• pp.149-153
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• 2016

Nanosized zeolites were prepared in an autoclave using tetraethoxysilane (TEOS), tetrapropylammonium hydroxide (TPAOH), and $H_2O$, at various hydrothermal synthesis temperatures. Using transmission electron microscopy and particle size analysis, the nanopowder particulate sizes were revealed to be 10-300 nm. X-ray diffraction analysis confirmed that the synthesized nanopowder was silicalite-1 zeolite. Using atomic layer deposition, the fabricated zeolite nanopowder particles were coated with nanoscale $TiO_2$ films. The $TiO_2$ films were prepared at $300^{\circ}C$ by using $Ti[N(CH_3)_2]_4$ and $H_2O$ as precursor and reactant gas, respectively. In the TEM analysis, the growth rate was ${\sim}0.7{\AA}/cycle$. Zeta potential and sedimentation test results indicated that, owing to the electrostatic repulsion between $TiO_2$-coated layers on the surface of the zeolite nanoparticles, the dispersibility of the coated nanoparticles was higher than that of the uncoated nanoparticles. In addition, the effect of the coated nanoparticles on the photodecomposition was studied for the irradiation time of 240 min; the concentration of methylene blue was found to decrease to 48%.