• 제목/요약/키워드: $LaNiO_3$

검색결과 174건 처리시간 0.023초

란탄 기반 페롭스카이트 촉매를 이용한 악취 유발 물질의 저온 산화 반응 (Low-temperature Oxidation of Odor Compounds over La-based Perovskite Catalyst)

  • 방용주;서정길;이기춘;박찬정;김형태;송인규
    • Korean Chemical Engineering Research
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    • 제49권2호
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    • pp.168-174
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    • 2011
  • La을 기반으로 하는 다양한 페롭스카이트 촉매를 페치니(Pechini)법에 따라 제조하고, 이 촉매를 음식물 처리 과정에서 발생하는 악취 성분의 저온 산화 반응에 적용하여 효과적인 탈취가 이루어지도록 하였다. 배출 가스의 정량 및 정성 분석을 통하여 음식물 처리 시간에 따른 주요 악취 성분의 양을 조사하였다. 그리고 주요 악취 성분들로 구성된 표준 악취 시료는 산화 반응기의 반응물로 도입하였다. 먼저, 다양한 전이 금속 M이 치환된 La 기반 페롭스카이트 촉매($LaMO_{3}$: M=Cr, Mn, Fe, Co 및 Ni)를 제조하고 전이 금속 M의 영향을 알아보기 위해 악취 성분의 산화 반응에 적용한 결과, 테스트한 촉매 중에서 $LaNiO_3$ 촉매가 가장 우수한 촉매 활성을 보였다. 또한 촉매 활성을 증진시키기 위하여 Pt가 치환된 페롭스카이트 촉매($LaNi_{1-x}Pt_{x}O_{3}$: x=0, 0.03, 0.1 및 0.3)를 제조하였고, 이로부터 $LaNi_{0.9}Pt_{0.1}O_{3}$ 촉매가 가장 효율적인 촉매인 것을 알 수 있었다. 끝으로 저온 산화 반응에서의 페롭스카이트 촉매의 활성을 극대화하기 위하여 담지된 페롭스카이트 촉매($XLaNi_{0.9}Pt_{0.1}O_{3}/Al_{2}O_{3}$: X=페롭스카이트 함량(wt%), 0, 10, 20, 30, 40, 50 및 100)를 적용하였다. $XLaNi_{0.9}Pt_{0.1}O_{3}/Al_{2}O_{3}$ 촉매의 활성은 페롭스카이트 함량에 따라 화산형(Volcano-shaped) 곡선을 나타내었으며, 이 때 $20LaNi_{0.9}Pt_{0.1}O_{3}/Al_{2}O_{3}$ 촉매가 $180^{\circ}C$의 반응 온도에서 88.7%의 가장 높은 전환율을 보였다.

Evidence of spin-phonon coupling in La2NiMnO6 double perovskite

  • Nasir, Mohammad;Ahmed, Ateeq;Park, Hee Jung;Sen, Somaditya
    • 한국결정성장학회지
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    • 제31권3호
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    • pp.112-115
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    • 2021
  • Herein, a correlation between B-site cation order and spin-phonon coupling in La2NiMnO6 double perovskite has been investigated. Raman spectra of La2NiMnO6 double perovskite annealed at 950 and 1400℃ have been measured in the 140-598 K range. A substantial softening of the phonon modes has been observed below the Curie temperature, which emphasized the presence of the spin-phonon coupling in the system. The spin-phonon coupling was found to be stronger in relatively more ordered La2NiMnO6 double perovskite. Thus, the magnitude of spin-phonon coupling was influenced by the Ni/Mn cation order.

Characteristics of LaCo1-xNixO3-δ Coated on Ni/YSZ Anode using CH4 Fuel in Solid Oxide Fuel Cells

  • Kim, Jun Ho;Jang, Geun Young;Yun, Jeong Woo
    • Journal of Electrochemical Science and Technology
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    • 제11권4호
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    • pp.336-345
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    • 2020
  • Nickel-doped lanthanum cobalt oxide (LaCo1-xNixO3-δ, LCN) was investigated as an alternative anode material for solid oxide fuel cells. To improve its catalytic activity for steam methane reforming (SMR) reaction, Ni2+ was substituted into Co3+ lattice in LaCoO3. LCN anode, synthesized using the Pechini method, reacts with yttria-stabilized zirconia (YSZ) electrolyte at high temperatures to form an electrochemically inactive phase such as La2Zr2O7. To minimize the interlayer by-products, the LCN was coated via a double-tape casting method on the Ni/YSZ anode as a catalytic functional layer. By increasing the Ni doping amount, oxygen vacancies in the LCN increased and the cell performance improved. CH4 fuel decomposed to H2 and CO via SMR reaction in the LCN functional layer. Hence, the LCN-coated Ni/YSZ anode exhibited better cell performance than the Ni/YSZ anode under H2 and CH4 fuels. LCN with 12 mol% of Ni (LCN12)-modified Ni/YSZ anode showed excellent long-term stability under H2 and CH4 conditions.

$La(Ni_{1-x}Cu_x)O_3$계 화합물의 상안정 및 전기적 특성 (The Phase Stability and the Electrical Properties of the System $La(Ni_{1-x}Cu_x)O_3$)

  • 변재동;선호정;송기영
    • 한국세라믹학회지
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    • 제28권11호
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    • pp.873-877
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    • 1991
  • The phase stability and the electrical properties of $La(Ni_{1-x}Cu_x)O_3$ (X=0.2, 0.4, 0.6, 0.8) have been investigated. The single phases were observed in the compositions of X=0.2, 0.4, and these single phases were stable up to $870^{\circ}C$ and $950^{\circ}C$ respectively. The electrical properties of these single phase samples showed metallic behavior similar to LaNiO3 from room temperature to the temperature at which the phase was stable.

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Si와 $Al_2O_3$ 기판에 대한 $LaNiO_3$ 박막의 배향성 형성과 도전도 (Formation and conductivity of oriented $LaNiO_3$ thin films on Si and $Al_2O_3$ substrates)

  • 김대영;박민석;손세모;이명교;김강언;정수태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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    • pp.799-802
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    • 2003
  • [ $LaNiO_3$ ](LNO) thin films were deposited on various substrates as Si and $Al_2O_3$ by sol-gel process using lanthanum nitrate and nickel acetate. The structure and orientation of the films were characterized by X-ray diffraction. The orientation factors of films on Si(100), Si(111), $SiO_2/Si(100)$ and $Al_2O_3$were 97%, 63%, 73%, and 24% respective. The conductivity was $7.6{\times}10^{-3}{\Omega}{\cdot}cm$ with 10 times coating at Si(100) substrate.

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졸-겔법으로 $LaNiO_3$ 전극에 증착된 $(Na_{0.5}Bi_{0.5})TiO_3$ 박막의 배향성 (Orientation of $(Na_{1/2}Bi_{1/2})TiO_3$ thin films deposited on $LaNiO_3$ electrodes by sol-gel methode)

  • 박민석;유영배;문병기;손세모;정수태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.894-897
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    • 2004
  • Sodum bismuth titanate $(Na_{0.5}Bi_{0.5}TiO_3$ or NBT) thin films coated on the $LaNiO_3$ (LNO) electrode by sol-gel methode and rapid thermal annealing (RTA) technique. The NBT (NBT/LNO/Si) thin films examined by x-ray diffraction (XRD). The orientation of NBT was observed for films coated at $900^{\circ}C$, 5 min and $600^{\circ}C$, 60 min. Filed emission scanning electron microscopy (FE-SEM) showed uniform surface composed of grains. The grain size of NBT thin films increased with increasing annealing temperature.

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MOD법으로 제작한 $Bi_{3.25}La_{0.75}Ti_3O_{12}/LaNiO_3$ 박막의 강유전 특성에 관한 연구 (Ferroelectric properties of $Bi_{3.25}La_{0.75}Ti_3O_{12}/LaNiO_3$ thin films prepared by metalorganic decomposition method)

  • 김경태;김창일;김태형;이철인
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.352-355
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    • 2003
  • [ $Bi_{3.25}La_{0.75}Ti_3O_{12}$ ] (BLT) thin films were prepared by using metal organic decomposition method onto the LaNiO3 (LNO) bottom electrode. Both the structure and morphology of the films were analyzed by x-ray diffraction (XRD) and atomic force microscope (AFM). Even at low temperatures ranging from 450 to $650^{\circ}C$, the BLT thin films were successfully deposited on LNO bottom electrode and exhibited (117) orientation. The BLT thin films annealed as low as $600^{\circ}C$ showed excellent ferroelectricity, higher remanent polarization and no significant degradation of switching charge at least up to $5{\times}10^9$ switching cycles at a frequency of 100 kHz and 5 V. For the annealing temperature of $600^{\circ}C$, the remanent polarization $P_r$ and coercive field were $23.5\;{\mu}C/cm^2$ and 120 kV/cm, respectively.

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LSGM계 고체산화물 연료전지의 전해질-음극 사이의 계면안정성 (Interfacial Stability Between Anode and Electrolyte of LSGM-Based SOFCs)

  • 김광년;문주호;손지원;김주선;이해원;이종호;김병국
    • 한국세라믹학회지
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    • 제42권7호
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    • pp.509-515
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    • 2005
  • Interfacial reactions at LSGM electrolyte and NiO-GDC anode interfaces were thoroughly investigated with Environmental Scanning Electron Microscopy (ESEM-PHlLIPS XL-30) and Energy Dispersive X-ray (EDX-Link XL30). According to the analysis, serious reaction zone was observed at LSGM/NiO-GDC interface. It was found that the reaction layer was originated from the chemical reaction between NiO and LSGM. The reaction products were identified as La deficient form of LSGM based perovskite and Ni-La-O compounds such as LaSrGa$_{3}$O$_{7}$ and LaNiO$_{3}$ from the X-Ray Diffraction (XRD, Philips) analysis. According to the electrical characterization, interfacial layer was very electrically resistive which would be the cause of high internal resistance and low power generating characteristic of the unit cell.

Li[Ni0.3Co0.4Mn0.3]O2 양극물질의 Li-La-Ti-O코팅 효과 (The Effects of Li-La-Ti-O Coating on the Properties of Li[Ni0.3Co0.4Mn0.3]O2 Cathode Material)

  • 이혜진;윤수현;박보건;유제혁;김관수;김석범;박용준
    • 한국전기전자재료학회논문지
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    • 제22권10호
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    • pp.890-896
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    • 2009
  • Li(Ni, Co, Mn)$O_2$ has been known as one of the most promising cathode materials for lithium secondary batteries. However, it has some problems to overcome for commercialization such as inferior rate capability and unstable thermal stability. In order to address these problems, surface modification of cathode materials by coating has been investigated. In the coating techniques, selection of coating material is a key factor of obtaining enhanced properties of cathode materials. In this work, we introduced solid electrolyte (Li-La-Ti-O) as a coating material on the surface of $Li[Ni_{0.3}Co_{0.4}Mn_{0.3}]O_2$ cathode. Specially, we focused on a rate performance of Li-La-Ti-O coated $Li[Ni_{0.3}Co_{0.4}Mn_{0.3}]O_2$ cathode. Both bare and Li-La-Ti-O 2 wt.% coated sample showed similar discharge capacity at 0.5C rate. However, as the increase of charge-discharge rate to 3C, the coated samples displayed better discharge capacity and cyclic performance than those of bare sample.