• Bulletin of the Korean Chemical Society
• /
• v.31 no.6
• /
• pp.1661-1664
• /
• 2010

The photocatalytic decomposition of toluene vapor by bare and $TiO_2$-coated carbon fibers was studied. Atomic layer deposition (ALD) was used to perform the $TiO_2$ coating. We show that, under our conditions, the photocatalytic activity of bare carbon fibers was comparable with that of $TiO_2$ films, which are known to be good photocatalysts. The origin of the high photocatalytic activity of bare carbon fibers is discussed.

• Journal of Korean Society for Atmospheric Environment
• /
• v.22 no.1
• /
• pp.43-51
• /
• 2006

Nonthermal plasma-driven catalysis (PDC) was investigated for the decomposition of benzene and toluene as model compounds of volatile organic compounds (VOCs) at atmospheric pressure and low temperature. Two types of catalysts Ag/$TiO_{2}$ and Pt/$\gamma-Al_{2}O_{3}$ were tested in this study. The amount of catalysts packed in the PDC reactor did not influence on the decomposition efficiency of benzene. The type of catalysts also had no influence on the decomposition efficiency of toluene and carbon balance. The Ag/$TiO_{2}$ catalyst showed constant $CO_{2}$ selectivity of about $73\%$ regardless of the specific input energy. However, the selectivity of $CO_{2}$ was greatly enhanced with the Pt/$\gamma-Al_{2}O_{3}$ catalysts, and reached $97\%$ at 205 J/L. Two test runs with 20 fold difference in the gas flow clearly indicated that lab-scale data can be successfully applied for the scaling-up of PDC system.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.1
• /
• pp.107-113
• /
• 2009

This study investigated the decomposition activities of toluene on 10 mol% Al-W-incorporated mesoporous titano (15 mol %) silicates. The mesopore sizes observed in the transmission electron microscopy images ranged from 2.0 to 5.0 nm, and the pores were irregular on the addition of 10 mol% Al or W ions, but changed to regular hexagonal forms with the simultaneous additions of Al and W. The X-ray photon spectroscopy results showed a shift of the special peak for Ti2p in Al-incorporated mesoporous titanosilicates to a stronger binding energy compared to those of mesoporous titanosilicates and Al-incorporated mesoporous titanosilicates. Three O1s peaks in the spectra of the Al and W coexisted samples were observed at 530.5 and 531.7, 533, and 533.7eV, which were assigned to $Ti-Os\;in\;TiO_2\;and\;Ti_2O_3,\;Si-O\;in\;SiO_2\;and\;Al-O\;in\;Al_2O_3$, respectively. The toluene molecules desorbed at lower temperatures over W-incorporated mesoporous titanosilicates, and the amounts of toluene desorbed were also small; however, Al-incorporated mesoporous titanosilicates adsorbed much more toluene, particular over $Al_7.5-W_2.5-Ti_15-Si_75$. The photocatalytic decomposition of toluene was more enhanced over $Al_7.5-W_2.5-Ti_15-Si_75$ than over Al- or W-incorporated mesoporous titanosilicates only.

• Journal of the Korean Applied Science and Technology
• /
• v.31 no.4
• /
• pp.541-548
• /
• 2014

This study was performed to obtain high conversion efficiency of $C_7H_8$ using non-thermal plasma and metal-supported catalyst. Adsorption-desorption characteristics of toluene was performed using 4A type (Zeolite) filled in a concentration reactor. Through this test, it was found that the concentration reactor has 0.020 g/g of adsorption capacity (at ambient temperature and pressure) and 3,600 ppm of desorption property at $150^{\circ}C$ (with in 20 min). In case of developed catalyst, toluene decomposition rate of Pd-AO (Pd coated catalyst) was better than Pd/Cu-AO and Pd/Ag-AO (Pd/Ag composite metal catalyst). Developed non-thermal plasma system was obtained flame amplification effect using injection process of desorbed tolune, and 98% of removal efficiency.

• Journal of Environmental Science International
• /
• v.22 no.8
• /
• pp.945-951
• /
• 2013

Alumina-supported catalysts containing different transition metals such as Cu, Cr, Mn, Zn, Co, W were investigated for their activity in the selective oxidation of toluene. Catalytic oxidation of toluene was investigated at atmospheric pressure in a fixed bed flow reactor system over transition metals with $Al_2O_3$ catalyst. The result showed the order of catalytic activities for the complete oxidation of toluene was Mn > Cu> Cr> Co> W> Zn for 5wt.% transition $metals/Al_2O_3$. $Mn/Al_2O_3$ catalysts containing different amount of Mn were characterized by X-ray diffraction spectroscopy for decision of loading amount of metal to alumina. 5 wt.%$Mn/Al_2O_3$ catalyst exhibits the highest catalytic activity, over which the toluene conversion was up to 90% at a temperature of $289^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.34-34
• /
• 2010

Activities of various $TiO_2$ nanostructures in photocatalytic decomposition of methylene blue and toluene were determined in order to shed light on the relationship between structures and photocatalytic activity. Commercially available P-25 samples were used in the present work. In addition, $TiO_2$ nanostructures were synthesized using atomic layer deposition (ALD). We show that change in the surface structure of $TiO_2$ upon variois surface treatments results in variation in photocatalytic activity. In particular, increase in the number of OH groups on the surface leads to the enhancement in photocatalytc activity. Surface OH groups increases adsorption reactivity of organic reactants, thereby increasing activity in photocatalytic decomposition of methylene blue and toluene.

• Journal of Korean Society for Atmospheric Environment
• /
• v.24 no.6
• /
• pp.641-648
• /
• 2008

A plate-type dielectric barrier discharge (DBD) reactor was designed and tested for removal of gaseous toluene. The DBD reactor consisted of 9 parallel plate electrodes, four of which were grounded. An AC voltage of rectangular waveform ($5{\sim}8.5kV$, $60{\sim}1,000Hz$), was applied to the other five electrodes. The gaseous toluene passed through the DBD reactor and its concentration was measured by a real-time gas analyzer. The carbon monoxide (CO) and carbon dioxide ($CO_2$) which were produced by decomposition of toluene in the DBD reactor, were sampled and analyzed by a micro gas chromatography. The maximum toluene removal efficiency was 51.4%.

• Journal of Environmental Science International
• /
• v.13 no.1
• /
• pp.37-40
• /
• 2004

In this study, the decomposition of gas-phase TCE, Benzene and Toluene, in air streams by direct UV Photolysis and UV/TiO$_2$ process was studied. For direct UV Photolysis, by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene and Benzene in this work were determined to be 0.00392s$\^$-l/, 0.00230s$\^$-1/ and 0.00126s$\^$-1/, respectively. And the adsorption constant K of TCE, Toluene and Benzene in this work were determined to be 0.0519 mol$\^$-l/ ,0.0313mo1$\^$-1/ and 0.0084mo1$\^$-1/, respectively. For UV/TiO$_2$ system by regressing with computer calculation to the experimental results the value of reaction rate constant k of TCE, Toluene, and Benzene in this work were determined to be 5.74g/$\ell$$.$min, 3.85g/$\ell$$.$min, and 1.18g/$\ell$$.$min, respectively. And the catalyst adsorption constant K of TCE, Toluene, and Benzene in this work were determined to be 0.0005㎥/mg, 0.0043㎥/mg and 0.0048㎥/mg, respectively.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2006.04a
• /
• pp.281-282
• /
• 2006

• International Journal of Safety
• /
• v.2 no.1
• /
• pp.28-33
• /
• 2003

Thermal decomposition characteristics of ethyl methacrylate (EMA) and Styrene (St.) copolymer was investigated with synthesis at 8$0^{\circ}C$ in a continuous stirred tank reacto (CSTR) using toluene and benzoyl peroxide(BPO) as solvent and initiator, respectively. The thermal decomposition was considered to be side scission at below 30$0^{\circ}C$ and estimated 2nd-order reaction kinetics of EMA/St. copolymer. The activation energies of decomposition on this copolymers were in the ranges of 38-43 kcal/mol for EMA/St. and a good additivity rule was observed in each composition. The thermogravimetric trace curves agreed well with the theoretical calculation.