• Clean Technology
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• v.19 no.2
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• pp.128-133
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• 2013

Catalytic combustion of benzene over $CeO_2$-supported copper oxides has been investigated. The supported copper oxides catalysts were prepared using ball mill method and characterized by XRD, FT-IR, TEM and TPR. In the CuO/$CeO_2$ catalysts prepared using ball mill method, highly dispersed copper oxide species were shown at high loading ratio. The CuO/$CeO_2$ prepared using ball mill method showed the higher activity than those prepared using impregnation method. The catalytic activity increased with an increase in the CuO loading ratio, 10 wt% loaded CuO/$CeO_2$ catalyst giving the highest activity. In addition, the promoting of 10 wt% loaded CuO/$CeO_2$ catalyst with $Fe_2O_3$ and CoO enhanced the dispersion of CuO and then increased the catalytic activity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.537-544
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• 2011

This work was conducted to investigate the oxidation characteristics of methane having the highest ignition temperature among the other hydrocarbon gases using transition metal catalysts. The catalyst used for methane oxidation was manganese oxide having a various oxidation number, such as MnO, $MnO_2$, $Mn_2O_3$, $Mn_3O_4$, $Mn_4O_5$. The manganese oxide(MnxOy) catalyst is impregnated on $TiO_2$, $Al_2O_3$ for methane oxidation. To enhanced both of activity and life time of catalysts, Ni and Co was used as a promoter. In this study, various co-catalysts were synthesized by using excess wet impregnation method. The effect of reaction temperature and space velocity was measured to calculate the activity of catalysts such as, activation energy of $T_{50}$, and $T_{90}$. The life time of bi-metallic manganese mixture, such as Mn-Co and Mn-Ni catalysts, were increased more 10 % than manganese oxide catalyst, but activity of those was decreased slightly.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.30-32
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• 2012

본 연구에서는 Cu, Mn을 함침 시킨 상용 제올라이트13X 촉매에 CO 산화 전환 반응에 영향을 연구하였다. 촉매 제조는 담지량별로 Cu, Mn을 서로 다른 비율로 물리 혼합하여 상용 제올라이트에 담지하였다. 함침방법은 과잉용액 함침법을 사용하였고, 건조 후 공기분위기에서 소성하여 산화물 형태로 담지하였다. 기본적인 촉매 특성은 X-선 회절분석, 질소흡탈착 등온곡선을 이용하여 기공크기, 기공부피, 비표면적을 구하였으며, FT-IR, 주사현미경, $NH_3$-TPD/TPR, EDX로 특성을 분석하였다. 촉매 산화반응 실험은 고정층 반응기에서 수행하였으며, 외경1/4 inch(내경 4 mm)석영관에 촉매를 중진하고 Gas Chromatograph로 배출가스를 측정하여 Cu-Mn 제올라이트 촉매의 일산화탄소 산화반응을 연구하였다. 일산화탄소 농도, 온도 및 공간속도, Cu-Mn 함량 비율에 따른 산화반응 실험을 수행하여 최적 산화조건과 촉매를 도출하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.164.2-164.2
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• 2016

수산화인회석(Hydroxyapatite)는 뼈와 이빨의 무기물의 주성분으로서 칼슘과 인산염으로 구성된다. 본 연구에서는 특정 농도의 염기조건 (10 M NaOH)에서 수열합성법 (hydrothermal method)을 이용하여 수산 화인회석을 합성하였다. 합성된 샘플은 XRD 패턴 및 TEM 이미지 분석을 통하여 단결정성과 일정한 형태를 지닌 수산화인회석이 합성된 것을 확인하였다. 수산화인회석의 표면에 루테늄을 도입하기 위하여 이온교환 반응 과 열처리 과정을 이용하였다. 도입된 루테늄 나노 입자는 TEM 이미지 분석을 통하여 확인하였으며, 일차알콜과 이차알콜등의 유기 산화반응에 촉매로서 사용하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.04a
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• pp.54-55
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• 1995

무기막은 고분자막에 비해서 고온에서의 사용이 가능하고 구조적 안정성 등이 우수한 특징이 있다. 이러한 무기막에 촉매를 담지하거나 코팅하여 분리막의 역할과 촉매로서의 역할을 동시에 수행하는 막반응기로의 응용이 가능하다. 본 연구에서는 Redox mechanism에 의한 부분산화반응을 일으키는 촉매인 오산화바나듐을 sol-gel법으로 코팅한 무기막을 제조하여, 막내부에 오산화바나듐의 격자산소를 이용하는 부분산화 반응물이 존재할 때 선택적으로 증가하는 산소의 투과특성을 조사하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.57.2-57.2
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• 2012

산소 이온 전도성 세라믹을 이용한 고체 산화물 연료전지의 전극은 원활한 전기화학반응을 위해, 이온 전도도, 전자 전도도 및 전기화학적 활성을 동시에 가지고 있어야 한다. 이를 위해 복합체 전극을 사용하며, 특히 음극의 경우 니켈(Nickel)과 Yttria-stabilized zirconia (YSZ)로 이루어진 복합체 전극을 혼합 및 소결을 통해 제조하여 사용하였다. 하지만, 니켈의 경우 탄화 수소 연료에서의 탄소 침적 문제와 열악한 산화환원 안정성(redox stability)등의 문제점을 가지고 있다. 따라서 니켈대신 전도성 세라믹을 사용한 세라믹 복합체 음극 개발이 활발히 이루어지고 있으며, 그 중 침투법(infiltration method)을 이용한 복합체 전극 제조 방법을 소개한다. 실제로 니켈 금속과 유사한 높은 전기 전도도를 갖는 Sr-doped Lanthanum Vanadate (LSV)을 이용해, YSZ-LSV 복합체 전극을 침투법을 이용해 제조하고, 소량의 촉매을 첨가하여, 이온전도도, 전자 전도도 및 촉매 활성을 갖는 복합체 음극을 제조하였다. 이 복합체 음극의 탄화수소에서의 연료전지 성능 및 redox stability을 측정하였다.

• Analytical Science and Technology
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• v.18 no.2
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• pp.130-138
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• 2005

Volatile organic compounds (VOCs) have been recognized as major contributor to air pollution. Catalytic oxidation in VOCs can give high efficiency at low temperature. In this study, monometallic Pt, Ir and bimetallic Pt-Ir were supported to $TiO_2$. Xylene, toluene and methyl ethyl ketone (MEK) were used as reactants. The monometallic or bimetallic catalysts were prepared by the excess wetness impregnation method and characterized by XRD, XPS and TEM analysis. Result reveal that Pt catalyst has higher conversion than Ir catalyst and Pt-Ir bimetallic catalysts. The existence of multipoint actives in, Pt-Ir bimetallic catalysts gives improved performance for the Pt metalstate. Bimetallic catalysts have higher conversion for VOCs than monometallic ones. The addition, VOCs oxidation follows first order kinetics. The addition of small amount of Ir to Pt promotes oxidation conversion of VOCs.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.4
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• pp.444-451
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• 2007

Catalytic oxidation characteristics of benzene as a VOC was investigated using a fixed bed reactor system over transition $metals/\gamma-Al_2O_3$ catalysts. As transition metals, eight metals including copper, nickel, manganese, iron etc. were adopted. The parametric tests were conducted at the reaction temperature range of $200\sim500^{\circ}C$, benzene concentration of $1,000\sim3,000$ ppm, and space velocity range of $5,000\sim60,000\;hr^{-l}$. The property analyses such as BET, SEM, XRD and the conversions of catalytic oxidation of VOC were examined. The experimental results showed that the conversion was increased with decreasing VOC concentration and space velocity. It was also found that $Cu/\gamma-Al_2O_3$ catalyst calcinated at $500^{\circ}C$ showed the highest activity for the oxidation of benzene and 15% metal loading was the optimum impregnation level.

• Clean Technology
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• v.20 no.3
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• pp.256-262
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• 2014

Catalytic oxidation characteristics of benzene as a VOC was investigated in a fixed bed flow reactor using $Cu/{\gamma}-Al_2O_3$ catalyst. The parametric tests were conducted at the reaction temperature range of $200{\sim}500^{\circ}C$, benzene concentration of 400~650 ppm, gas flow rate of 50~100 cc/min, and space velocity range of $7,500{\sim}22,500hr^{-1}$. The property analyses by using the BET, SEM, TGA and the conversion of catalytic oxidation of benzene were examined. The experimental results showed that the conversion was increased with decreasing benzene concentration, gas flow rate and space velocity. Benzene oxidation reaction over $Cu/{\gamma}-Al_2O_3$ catalyst could be expressed as the first order homogeneous reaction of which the activation energy was 17.2 kcal/mol and frequency factor was $1.33{\times}10^6sec^{-1}$.

• Journal of Energy Engineering
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• v.7 no.1
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• pp.35-43
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• 1998

Electrodes using for the anode electrode of direct methanol fuel cell with Pt/C and Pt/Ru/C catalyst were prepared and characterized by SEM, TEM, thermal analysis and electrochemical analysis. The half cell tests were carried out with 1 M $H_2SO_4$ electrolyte and 1 M $CH_3OH$ in order to evaluate the electrode performance. The employed electrochemical methods were cyclic vol-tammetry and potentiodynamic polarization experiments. It was found that 20 w% polytetrafluoroethylene (PTFE) content in catalyst showed the best performance due to the best platinum utilization on PTFE-containing catalyst layer. It was found that Pt/Ru/C binary catalyst inhibited the poisoning of anode electrode showing improved performance compared to the Pt/C catalyst by the adsorption of oxygen containing species on the electrode surface at same time. The apparent activation energy for methanol oxidation on the Pt/Ru/C and Pt/C catalyst layer was 11.60 kJ/mol and 26.85 kJ/mol, respectively.