• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.894-897
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• 2009

$\gamma-Al_2O_3$, $TiO_2$, ZrO에 Pt, Pd, Rh, Ru의 귀금속촉매를 분산하였으며, 촉매 분산은 과잉용액함침법으로 제조하였다. 저온에서 높은 산화능을 지닌 최소화된 귀금속의 함침량을 도출하기 위하여 연구를 수행하였다. 귀금속 촉매의 조성에 대한 영향을 도출하기 위하여 Rh, Pt, Pd, Ru에 대하여 조성과 함침량에 대하여 연구를 수행하였다. 충전층 반응기 및 모노리스 반응기를 이용한 촉매산화반응 실험결과 50% 전환온도 및 90% 전환온도를 측정한 결과 최적의 조성은 Pt-Rh /$Al_2O_3$ 촉매로 판명되었다.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.2
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• pp.95-101
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• 1995

Experiments have been conducted to investigate the characteristics of formaldehyde and nitrous oxide formation from the catalytic reaction of methane. Catalysts used in the experiment were Pd. Pd/Pt/Rh loaded on ${\gamma}-Al_2O_3$ and ${\gamma}-Al_2O_3-La_2O_3$ monolith. In the catalytic reaction of methane. as the concentration of NO, $O_2$ and $CH_4$ increased, the formaldehyde emission was increased. The concentration of $N_2O$ increased as NO and CO increased. It was also found that the formaldehyde emission was produced by the gas reaction of methane in high temperature above 950K.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1995.10a
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• pp.62-63
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• 1995

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.3
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• pp.249-255
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• 1999

We sdudied effect of additives on catalytic activity in thermal catalytic de-NOx process which was composed of thermal reduction, catalytic reduction and catalytic oxidation stage. Pd-Pt/${\gamma}$-$Al_2O_3$ catalysts with the addition of transition metals(Co, Cu, Fe, Ni, W, Zn, Zr) and rare earth metals(Ce, Sr) were prepared by the conventional washcoating method. Those catalysts were characterized by CO pulse chemisorption, ICP, $N_2$ adsorption, SEM and XRD. The effect of catalyst additives on NOx removal for diesel emission was studied in thermal catalytic de-NOx process at reduction temperature(350~50$0^{\circ}C$), space velocity(5,000~20,000 $hr^{-1}$) and the engine load(0~120kW). The concentraton of CO, $CO_2$, NO and $NO_2$ in the exhaust gas increased with the engine load. On the other hand the concentration of $O_2$ decreased. The de-NOx activityof all prepared catalysts increased with respect to high CO and low $O_2$ level in the thermal reduction stage of the process. Insertion of Ce to Pt-Pd/${\gamma}$-$Al_2O_3$ catalyst showed the best activity of all the catalysts under these experimental conditions. De-NOx catalysts are effective to remove CO in addition to NOx in the catalytic reduction stage.

• Clean Technology
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• v.16 no.1
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• pp.19-25
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• 2010

In this work, the conversion of crystalline cellulose into polyols in the presence of hydrogen was examined over noble metal (Pt, Ru, Ir, Rh, and Pd) catalysts supported on activated carbon. For comparison, Pt/${\gamma}-Al_2O_3$ and Pt/H-mordenite were also investigated. Several techniques: $N_2$ physisorption, X-ray diffraction(XRD), inductively-coupled plasma-atomic emission spectroscopy (ICP-AES), temperature-programmed reduction with $H_2$ ($H_2$-TPR) and CO chemisorption were employed to characterize the catalysts. The cellulose conversion was not strongly dependent on the types of the catalyst used. Pt/AC showed the highest yields to polyols among activated carbon-supported noble metal catalysts, viz. Pt/AC, Ru/AC, Ir/AC, Rh/AC and Pd/AC.

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

• Journal of Sensor Science and Technology
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• v.3 no.1
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• pp.32-39
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• 1994

Catalytic combustion type sensor was fabricated for alcohol detection, and its characteristics were tested. When the resistance of Pt coil for pellistor is 2.0 ohm, suggestible input power to bridge circuit was about 300 mW for methanol detection, and in the range from 350 mW to 400 mW for ethanol. Pellistors were prepared by means of impregnating Pt or Pd on the ${\gamma}$-alumina bead for sensing element, and transition metals such as $Co_{3}O_{4}$, $Fe_{2}O_{3}$ for compensating element.

• Journal of Sensor Science and Technology
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• v.8 no.4
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• pp.327-332
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• 1999

Catalytic combustion type gas sensors were fabricated by using noble metal(Pt and Pd) added ${\gamma}-Al_2O_3$ powder with specific surface area of $200\;m^2/g$. The fabricated sensor showed power consumption of 500 mW at the operating voltage of 1.75 V and high sensitivity of about 120 mV for butane, methane, or propane 100%LEL, respectively. The sensor properties also showed good linearity to hydrocarbon gas concentration variation, reproductivity and stability for relative humidity variation. And it showed high stability in butane ambient for 100 days.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.5
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• pp.26-34
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• 2008

The performance of several catalysts to decompose the high test peroxide (HTP) was described in this paper. Manganese oxide, Platinum and Iridium were coated on the gamma alumina. The catalyst activity as active materials was measured at the flask reactor. The response time of various catalysts was also measured with a 50 Newton class thruster. $Ir/Al_2O_3$ that showed the best activity in the flask reactor and response time at the thruster, failed the reaction when continuous mode test was carried out with the thruster. $Pt/Al_2O_3$ and $MnO_2/Al_2O_3$ can be substitutes to decompose the HTP. In addition, for larger thruster, $MnO_2/Al_2O_3$ can be a good catalyst because its cost is below 5 % of $Pt/Al_2O_3$.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.1
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• pp.51-58
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• 2002

Destruction process of toluene using a wire-cylindrical BBD (Dielectric Barrier Discharge) reactor packed with catalysts was investigated to characterize the synergetic effects of non-thermal plasma and catalyst process. The catalysts used in the present study were ${\gamma}$-Al$_2$BO$_3$ and Pt/${\gamma}$-Al$_2$O$_3$. Under the numerous test conditions, specific energy density (SED (J/L)) and the conversion of toluene, defined as (1 -[C$_{f}$]/[C$_{i}$]), were measured. The test results showed that toluene decomposition efficiency followed the pseudo-first order in the case of plasma only process. The pseudo-first order process, however, was modified to pseudo-zeroth order reaction in the case of catalyst-assisted plasma process. This modification of the reaction order was verified based on a simple kinetic model proposed in the present study. Owing to the modification of reaction order, which resulted from the catalytic process, the specific energy to achieve the high removal efficiencies, i.e. 80~90%, was reduced significantly.y.y.