• 대한화학회지
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• 제61권5호
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• pp.296-298
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• 2017

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2005년도 추계학술강연 및 발표대회강연 및 발표논문 초록집
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• pp.54-55
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• 2005

• Journal of Applied Biological Chemistry
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• 제43권4호
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• pp.207-210
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• 2000

As a typical example of the screening for a microbial biocatalyst from nature, isolation of nitrilesynthesizing microorganisms, characterization of a new enzyme aldoxime dehydratase, and its function in the aldoxime-nitrile pathway are introduced. Catalytic properties of some of our enzymes were improved through a direct evolutionary approach.

• Nuclear Engineering and Technology
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• 제7권1호
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• pp.9-14
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• 1975

슬레이트에 단량체 methyl methacrylate를 침투시키고 감마선 및 촉매 가열법으로 중합시켜 슬레이트-플라스틱 복합체를 제조하였다. 제품의 성질은 휨강도, 내수성 내산성등에 현저한 증가를 나타내었으며, 중합조건에 의한 차이점도 그 원인과 함께 비교 검토하였다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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• pp.354-359
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• 2001

CNTs were added to Ultra-high molecular weight polyethylene (UHMWPE) to improve the tribological properties of UHMWPE. CNTs which have a diameter of about 10-50nm, while their length is about 3-5nm were produced by the catalytic decomposition of tile C$_2$H$_2$ using a tube furnace. UHMWPE/CNTs composites were fabricated by hot pressing method. It is shown that friction coefficient was increased and wear resistance was improved as CNTs were added to UHMWPE because of excellent mechanical properties of CNTs located on UHMWPE surface.

• 한국재료학회지
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• 제22권6호
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• pp.316-320
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• 2012

$Co_3O_4$, $Al_2O_3$ and $Co_3O_4$/$Al_2O_3$ mesoporous powders were prepared by a sol-gel method with starting matierals of aluminum isopropoxide and cobalt (II) nitrate. A P123 template is employed as an active organic additive for improving the specific surface area of the mixed oxide by forming surfactant micelles. A transition metal cobalt oxide supported on alumina with and without P123 was tested to find the most active and selective conditions as a heterogeneous catalyst in the reaction of styrene epoxidation. A bBlock copolymer-P123 template was added to the staring materials to control physical and chemical properties. The properties of $Co_3O_4$/$Al_2O_3$ powder with and without P123 were characterized using an X-ray diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), a Bruner-Emmertt-Teller (BET) surface analyzer, and $^{27}Al$ MAS NMR spectroscopy. Powders with and without P123 were compared in catalytic tests. The catalytic activity and selectivity were monitored by GC/MS, $^1H$, and $^{13}C$-NMR spectroscopy. The performance for the reaction of epoxidation of styrene was observed to be in the following order: [$Co_3O_4$/$Al_2O_3$ with P123-1173 K > $Co_3O_4$/$Al_2O_3$ with P123-973 K > $Co_3O_4$-973 K>$Co_3O_4$/$Al_2O_3$-973 K > $Co_3O_4$/$Al_2O_3$ with P123-1473 K > $Al_2O_3$-973 K]. The existence of ${\gamma}$-alumina and the nature of the surface morphology are related to catalytic activity.

• 공업화학
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• 제28권3호
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• pp.279-285
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• 2017

본 연구에서는 $200{\sim}350^{\circ}C$의 범위에서 $NH_3$를 제어하기 위한 선택적 촉매 산화법(SCO)의 연구를 수행하였다. 제조된 촉매들의 물리화학적 특성을 확인하기 위하여 XRD, XPS 분석을 수행하였다. 열처리 조건에 따른 촉매의 반응활성은 수소로 환원시킨 촉매가 소성한 촉매보다 우수한 활성을 나타냈으며, XPS 분석을 통하여 환원촉매의 산화가 비율은 주로 $Pt^{2+}$와 $Pt^0$가 존재하는 것을 확인할 수 있었다. 또한 환원온도에 따른 $Pt/TiO_2$ 촉매의 반응활성을 비교해본 결과 $700^{\circ}C$에서 환원한 촉매가 가장 우수한 $NH_3$ 전환율을 나타냈으나, $N_2$로의 전환율은 $600^{\circ}C$에서 환원한 촉매가 가장 우수한 것을 확인하였다.

• 한국재료학회지
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• 제27권2호
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• pp.94-99
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• 2017

Dinickel-silicide $(Ni_2Si)/glass$ was employed as a counter electrode for a dye-sensitized solar cell (DSSC) device. $Ni_2Si$ was formed by rapid thermal annealing (RTA) at $700^{\circ}C$ for 15 seconds of a 50 nm-Ni/50 nm-Si/glass structure. For comparison, $Ni_2Si$ on quartz was also prepared through conventional electric furnace annealing (CEA) at $800^{\circ}C$ for 30 minutes. XRD, XPS, and EDS line scanning of TEM were used to confirm the formation of $Ni_2Si$. TEM and CV were employed to confirm the microstructure and catalytic activity. Photovoltaic properties were examined using a solar simulator and potentiostat. XRD, XPS, and EDS line scanning results showed that both CEA and RTA successfully led to tne formation of nano $thick-Ni_2Si$ phase. The catalytic activity of $CEA-Ni_2Si$ and $RTA-Ni_2Si$ with respect to Pt were 68 % and 56 %. Energy conversion efficiencies (ECEs) of DSSCs with $CEA-Ni_2Si$ and $RTA-Ni_2Si$catalysts were 3.66 % and 3.16 %, respectively. Our results imply that nano-thick $Ni_2Si$ may be used to replace Pt as a reduction catalytic layer for a DSSCs. Moreover, we show that nano-thick $Ni_2Si$ can be made available on a low-cost glass substrate via the RTA process.

• 공업화학
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• 제3권4호
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• pp.722-729
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• 1992

몇 종류의 산화물을 혼합하여 그 장점들이 촉매의 특성으로 나타나도록 하는 복합산화물 촉매의 한 종류로서 스피넬 구조를 이루는 Mg- 및 Bn-페라이트를 촉매로 선정하여 K 첨가에 따른 물성을 분석하고 페라이트상에서 에틸벤젠의 탈수소반응에 대하여 연구하였다. 촉매의 특성분석에는 XRD, BET법, DTA, XPS, TEM, TPD 등의 분석기법을 사용하였다. 페라이트 촉매에 대한 K 첨가 효과를 검토하기 위하여 물성을 종합적으로 분석한 결과, K는 입자의 분산도를 향상시키는 구조적 조촉매로서의 역할과 함께 전자를 공급하는 조촉매로서 작용하였으며, K의 첨가량이 증가함에 따라 산점이 중화되어 그 세기가 약해지면서 산점의 농도는 증가하였다. 반응성을 연구한 결과 페라이트 촉매에 첨가된 K는 강한 산점을 중화시켜 탈수소 반응에 적합한 세기의 산점을 형성하여 스티렌의 선택도를 일정하게 유지하였다.

• 한국분말재료학회지
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• 제8권3호
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• pp.163-167
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• 2001

A bulk porous $CaZrO_3/MgO$ composite with plantinum nano-dispersion was synthesized in air atmosphere through the combination of several in situ reactions, including the pyrolysis of $PtO_2$. A mixture of $CaMg(CO_3)_2$(dolomite), $ZrO_2$, $PtO_2$ and LiF (0.5 wt%, as an additive) was cold isostatically pressed at 200 MPa and sintered at $1100^{\circ}C$ for 2 h. The porous $CaZrO_3/MgO/Pt$ composite ($CaZrO_3/MgO$ : Pt=99 : 1 in volume) had a uniformly open-porous structure (porosity: 56%) with three-dimensional (3-D) network and a narrow pore-size distribution, similarly to the porous $CaZrO_3/MgO$ composites reported before. Catalytic Properties (viz., NO direct decomposition and NO reduction by $C_2H_4$) of the $CaZrO_3/MgO/Pt$ composite were investigated up to $900^{\circ}C$. In the absence of oxygen, the NO conversion rate reached ~52% for the direct decomposition and ~100% for the reduction by $C_2H_4$, respectively. The results suggest the possibility of the porous composite as a multifunctional filter, i.e., simultaneous hot gas-filtering and $de-NO_x$ in one component.