• 전기화학회지
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• 제25권2호
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• pp.69-80
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• 2022

고순도 수소생산을 위한 음이온 교환막 수전해는 양성자 교환막 수전해 시스템에서 사용되는 기존 귀금속 촉매 대신 저렴한 비귀금속 기반 촉매를 사용하여 차세대 녹색 수소 생산 기술로 많은 관심을 받고 있다. 하지만 음이온 교환막 수전해 기술은 개발 초기 단계이기 때문에 음이온 교환막 수전해의 핵심 요소인 음이온 교환막, 이오노머, 전극지지체 및 촉매에 관한 연구 수행이 필요하다. 그 중, 현재 촉매 분야에서 진행되고 있는 연구들은 기개발된 알칼리용 반쪽전지 촉매를 음이온 교환막 시스템에 적용하는 방향의 연구가 진행되고 있으며 적용된 촉매는 낮은 활성도와 내구성의 문제점을 가진다. 이에 본 총설은 알칼리성 매질에서 비귀금속 기반 촉매를 사용하여 산소발생반응 및 수소발생반응을 촉진시킨 촉매 합성 기술을 제시하였다.

• 대한화학회지
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• 제68권2호
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• pp.87-92
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• 2024

The commercialization of rechargeable metal-air batteries is extremely desirable but designing stable oxygen reduction reaction (ORR) catalysts with non-noble metal still has faced challenges to replace platinum-based catalysts. The nonnoble metal catalysts for ORR were prepared to improve the catalytic performance and stability by the thermal decomposition of ZIF-8 with optimum cobalt loading. The porous carbon was obtained by the calcination of ZIF-8 and different loading amounts of Co nanoparticles were anchored onto porous carbon forming a Co/PC catalyst. Co/PC composite shows a significant increase in the ORR value of current and stability (500 h) due to the good electronic conductive PCN support and optimum cobalt metal loading. The significantly improved catalytic performance is ascribed to the chemical structure, synergistic effects, porous carbon networks, and rich active sites. This method develops a new pathway for a highly active and advantageous catalyst for electrochemical devices.

• 대한기계학회논문집B
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• 제21권6호
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• pp.822-829
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• 1997

A catalytic burner was studied which can be used as a heater operated in medium temperature. Noble metal catalysts (Pd/NiO) were used, which were supported on alumina wash coated honeycomb. The maximum heat-resisting temperature of the catalyst is about 900.deg. C. Combustion efficiency of the catalytic burner reached more than 99.5 % at the excess air ratio above 1.25.NOx emissions were lower than 1.0 ppm at all operation conditions. The operation condition for a stable catalytic combustion was obtained. It was dependent on the catalyst thickness. The 30 mm thick catalyst showed the widest stable catalytic combustion region. Stable catalytic combustion region of 30 mm thick catalyst was the operation condition of excess air ratio 1.25 - 1.75 and heat flux 7 - 14 kcal/h center dot cm$^{2}$.

• 공업화학
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• 제35권2호
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• pp.134-139
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• 2024

메탄의 수증기 개질 반응에서 Ni 기반 촉매에 귀금속 Ru 및 Pd을 조촉매로 첨가하여 촉매의 활성 및 수소 생산에 미치는 영향을 분석하였다. 합성된 촉매는 허니컴 구조의 금속 모노리스 구조체 표면에 코팅하여 수증기 메탄 개질 반응을 수행하였다. 촉매의 특성은 XRD, TPR 및 SEM으로 분석하였으며 개질 반응 후 가스를 포집하여 GC로 조성을 분석한 후 메탄의 전환율, 수소 수율 및 CO 선택도를 측정하였다. 0.5 wt%의 Ru 첨가는 Ni의 환원 특성을 개선하였고, 99.91%의 메탄 전환율로 향상된 촉매 활성을 나타내었다. 또한, 다양한 공정 조건에 따른 반응 특성을 분석하였으며, 800 ℃의 반응 온도, 10000 h^-1 이하의 공간속도(GHSV), 3 이상의 H₂O와 CH₄의 비(S/C)에서 90% 이상의 메탄 전환율과 3.3 이상의 수소 수율을 얻을 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• 제20권4호
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• pp.43-49
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• 1996

With the recent interest in methanol as a SI engine fuel, aldehyde emissions have become a greater concern. A M-90 fueled passenger car was operated in a chassis dynamometer using FTP 75 driving cycle to examine formaldehyde emissions. Formation process of aldehyde and methods to reduce them are discussed in this paper for a SI-engine passenger car operating by M-90. Aldehyde emissions have been found to be 3 to 7 times higher from M-90 than from gasoline, while CO, NOx, THC are as low or lower than gasoline. Noble metal compositions appeared to play a role in formaldehyde and unburned methanol emission performance. For example, catalyst Pd showed better reduction of both formaldehyde and methanol than catalyst Pt. however, emission rates of formaldehyde and methanol for catalyst Pt were relatively similar to catalyst Pt/Rh.

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.415-423
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• 2011

HI decomposition step certainly demand catalytic reaction for efficient production of hydrogen in SI process. Platinum catalyst can apply to HI decomposition reaction as well as hydrogenation or dehydrogenation. Generally, noble metal is used as catalyst which is loaded form for getting high dispersion and wide active area. In this study, Pt was loaded onto zirconia, ceria, alumina, and silica by impregnation method. HI decomposition reaction was carried out under the condition of $450^{\circ}C$, 1atm, and $167.76h^{-1}$ (WHSV) in a fixed bed reactor for measuring catalytic activity. And property of a catalyst was observed by BET, TEM, XRD and chemisoption analysis. On the basis of experimental results, we discussed about conversion of HI according to physical properties of the loaded Pt catalyst onto each support.

• 한국대기환경학회지
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• 제6권1호
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• pp.57-72
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• 1990

The oxidation of carbon monoxide on a catalyst, $LaSrNiCoO_3$ was investigatigated with a plug flow system. Kinetic quantities such as reaction-rate, reaction order and Arhenius-parameters at various reactor temperature from 200$^\circ$C to 300$^\circ$C were determined. Also, the optimum condition for the oxidation of carbon monoxide with this catalyst was determined and are as follows. Partial pressure of oxigen ; 428mmHg Partial pressure of carbon monoxide ; 332mmHg Mixed moral ratio of oxigen and Carbon monoxide ; 1.3 : 1 Total gas flow ; 224ml/min Reaction temperature ; 340$^\circ$C The reaction kinetic equation at the optimum condition, temperature range from 200$^\circ$C to 340$^\circ$C, are as follow. $$ $v = Ae^{6.5Kcal/RT} [CO]^{0.93 \sim 0.98} [O_2]^{0.42 \sim 0.50}$ $$ In addition to this, numerical calculation were performed to evaluate the mass and heat transfer effect on this system.

• 분석과학
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• 제19권5호
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• pp.422-432
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• 2006

VOC는 대기오염의 주원인으로서 인식되어왔다. 촉매산화는 저온에서 높은 효율을 나타내기 때문에 VOCs 제거를 위한 가장 중요한 처리기술중 하나이다. 이 연구에서는 ${\gamma}-Al_2O_3$ 담체에 Pt, Pt-Ru 그리고 Pt-Ir을 담시지켜 촉매를 제조하였다. 반응물로서 Xylene, toluene 그리고 MEK를 사용하였다. 단일 또는 두 가지 이상의 촉매들은 함침법에 의해 준비하였고, XRD, XPS, TEM, BET 분석을 통하여 특성화하였다. 그 결과 Pt-Ru, Pt-Ir 촉매는 Pt 촉매에 비해 더 높은 전환율을 나타내었다. ${\gamma}-Al_2O_3$ 담체상에서 Pt-Ir 촉매가 가장 높은 전환율을 보인다. VOCs산화에서, Pt-Ru, Pt-Ir 촉매는 다양한 활성점을 나타내었고 그것은 Pt의 metal 영역를 강화시켰다. 따라서 두 가지 금속으로 이루어진 촉매가 단일 금속으로 이루어진 촉매에 비해 VOCs 전환율이 더 높았다. 이 연구에서 Pt에 소량의 Ru, Ir 첨가는 VOCs의 산화반응을 증진시켰다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.86-86
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• 2012

The new approaches for silicon solar cell of new concept have been actively conducted. Especially, solar cells with wire array structured radial p-n junctions has attracted considerable attention due to the unique advantages of orthogonalizing the direction of light absorption and charge separation while allowing for improved light scattering and trapping. One-dimenstional semiconductor nano/micro structures should be fabricated for radial p-n junction solar cell. Most of silicon wire and/or pillar arrays have been fabricated by vapour-liquid-solid (VLS) growth because of its simple and cheap process. In the case of the VLS method has some weak points, that is, the incorporation of heavy metal catalysts into the growing silicon wire, the high temperature procedure. We have tried new approaches; one is electrochemical etching, the other is noble metal catalytic etching method to overcome those problems. In this talk, the silicon pillar formation will be characterized by investigating the parameters of the electrochemical etching process such as HF concentration ratio of electrolyte, current density, back contact material, temperature of the solution, and large pre-pattern size and pitch. In the noble metal catalytic etching processes, the effect of solution composition and thickness of metal catalyst on the etching rate and morphologies of silicon was investigated. Finally, radial p-n junction wire arrays were fabricated by spin on doping (phosphor), starting from chemical etched p-Si wire arrays. In/Ga eutectic metal was used for contact metal. The energy conversion efficiency of radial p-n junction solar cell is discussed.

• 분석과학
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• 제23권4호
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• pp.383-388
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• 2010

폐플라스틱을 오일로 전환하기 위하여 귀금속이 담지된 촉매를 사용하여 촉매 분해반응을 연구 하였다. 제조된 촉매의 결정 구조, 결정형태, 접촉분해 후 생성물의 분포를 알고자 XRD, SEM, GC/MSD 등의 분석을 시행하였다. 접촉분해 반응은 열분해반응에 비해서 저온에서 일어나며, 열분해생성물이 $C_1\simC_4$의 가스상이 대부분인데 비해, 액상화합물이 많아 휘발유 생성에 유리한 면이 있다. 접촉 분해반응결과 휘발유 성분이 많이 생성되었다. 귀금속이 담지된 촉매중 Pt-zeolite 촉매가 $340^{\circ}C$에서 $C_5\simC_{11}$ 근처의 휘발유 성상의 생성물 분포가 가장 많이 나타났으며, $340^{\circ}C$ 이상부터는 폐플라스틱(PE, PP, ABS)에 대해서 접촉 분해반응 전환율이 약 70% 이상인 것으로 나타났다.