• Title/Summary/Keyword: Ru/C

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Effect of Tungsten on PtRuW/C Catalysts for Promoting Methanol Electro-oxidation (메탄올 전기산화반응 증진을 위한 PtRuW/C 촉매에서 텅스텐의 효과에 관한 연구)

  • Noh, Chang Soo;Sohn, Jung Min;Park, Young-Kwon
    • Applied Chemistry for Engineering
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    • v.23 no.6
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    • pp.561-566
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    • 2012
  • PtRuW/C catalysts were prepared with the different molar ratios of Pt : Ru : W and their compositions were analyzed by energy dispersive X-ray (EDX). The uniform distribution of particles was observed using transmission electron microscopy (TEM). An average crystalline size of 3.5~5.5 nm was calculated based on x-ray diffraction (XRD) data. The electrochemical properties such as electrochemically active surface areas, current densities, specific activities and poisoning rates, were analyzed via CO stripping, linear sweep voltammetry and chronoamperometry. From the analysis, we observed that ternary alloy catalysts, except $PtRu_2W_2/C$, have higher current densities, specific activities and stabilities than those of commercial binary catalysts. Among all in-house catalysts, Pt5Ru4W/C showed the highest specific activity of $121.05mA{\cdot}m^{-2}$ and the lowest poisoning rate of $0.01%{\cdot}s^{-1}$.

Microstructural Characterization of MOCVD RuOx Thin Films and Effects of Annealing Gas Ambient (MOCVD RuOx 박막의 미세구조 특성평가와 열처리 가스환경 영향)

  • Kim, Gyeong-Won;Kim, Nam-Su;Choe, Il-Sang;Kim, Ho-Jeong;Park, Ju-Cheol
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.9
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    • pp.423-429
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    • 2002
  • RuOx thin films were fabricated by the method of liquid delivery MOCVD using Ru(C$_{8}$ $H_{13}$ $O_2$)$_3$ as the precursor and their thermal effects and conductivity were investigated. Ru films deposited at 25$0^{\circ}C$ were annealed at $650^{\circ}C$ for 1min with Ar, $N_2$ or N $H_3$ ambient. The changes of the micro-structure, the surface morphology and the electrical resistivity of the Ru films after annealing were studied. Ar gas was more effective than $N_2$ and N $H_3$ gases as an ambient gas for the post annealing of the Ru films, because of smaller resistivity and denser grains. The X-ray diffraction and X-ray photoelectron spectroscopy results indicate that the Ru $O_2$ phase and the silicidation are not observed regardless of the ambient gases. The minimum resistivity of the Ru film is found to have the value of 26.35 $\mu$Ω-cm in Ar ambient. Voids were formed at Ru/TiN interface of the Ru layer after annea1ing in $N_2$ ambient. The $N_2$ gas generated due to the oxidation of the TiN layer accumulated at the Ru/TiN interface, forming bubbles; consequently, the stacked film may peel off the Ru/TiN interface.e.

Anisotropic Silicon Etching Using $RuO_2$ Thin Film as a Mask Layer by TMAH Solution ($RuO_2$를 마스크 층으로 TMAH에 의한 이방성 실리콘 식각)

  • 이재복;오세훈;홍경일;최덕균
    • Journal of the Korean Ceramic Society
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    • v.34 no.10
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    • pp.1021-1026
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    • 1997
  • RuO2 thin film has reasonably good conductivity and stiffness and it is thought to substitute for the cantilever beam made up of Pt and Si3N4 double layers in microactuators. Therefore, anisotopic Si etching was performed using RuO2 thin film as a mask layer in 25 wt. % TMAH water solution. In the etching temperature ranging from 6$0^{\circ}C$ to 75$^{\circ}C$, the etch rates of all the crystallographic directions increased linearly as the etching temperature increased. The etch rate ratio(selectivity) of [111]/[100] which varied from 0.08 to 0.14, was not sensitive to temperature. The activation energies for [110] direction, [100] direction and [111] direction were 0.50, 0.66 and 1.04eV, respectively. RuO2 cantilever beam with a clean surface was formed at the etching temperatures of 6$0^{\circ}C$ and $65^{\circ}C$. But the damages due to formation of pin holes on RuO2 surface were observed beyond 7$0^{\circ}C$. The tensile stress of RuO2 thin films caused the cantilever bending upward. As a result, it was demonstrated that the formation of conducting oxide RuO2 cantilever beam which can replace the role of an electrode and supporting layer could be possible by TMAH solution.

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Phase Transitions Mechanisms of Ru Based Thick Film Resistors (Ru 계 후막저항계의 상전이 기구)

  • 강병돈
    • Journal of the Microelectronics and Packaging Society
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    • v.1 no.2
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    • pp.125-134
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    • 1994
  • 저항범위가 다른 두종류의 Ru계 후막저항계(1Kohm/sq. 100kohm/sq.)를 선택하여 도전상의 상전이 기구를 반응조건을 변화시켜 연구하였다. 저저항체의 경우 도전상으로는 RuO2였으며 700-100$0^{\circ}C$에서 1시간 반응한 경우 반응온도에 따른 구성상의 변화는 없었다 반응온도 90$0^{\circ}C$에서 반응시간이 경과함에 따라 도전상은 RuO2가 Glass의 구성성분인 Pb와 반응하여 Rb2(Ru1.69 Pb0.31)O6.5로 변하고 시간이 36시간 경과한 후에는 도전상이 Pb4Al2Si2O10인 결정으로 둘러 쌓이는 반응인 peritectic reaction이 일어났다. 고전항체의 경 우 도전상으로는 Pb2(Ru1.69 Pb0.31)O6.5로 변하고 시간이 36시간 경과한 후에는 더전상이 Pb4Al2Si2O10인 결정으로 둘러쌓이는 반응인 peritectic reaction 이 일어났다. 고저항체의 경 우 도전상으로는 Pb2(Ru1.69 Pb0.31)O6.5인 pyrochrole 상이였다. 100$0^{\circ}C$에서 1시간 반응시킬 경 우 도전상이 RuO2로 변하였다. 반응온도를 90$0^{\circ}C$로 하고 반응시간을 변화시키면 도전상인 Pb2(Ru1.69 Pb0.31)O6.5가 (Ru1.69Pb0.31)O4x로 변하면서 공존하였다.

Ru-SiC schottky diode fabrication and characterisation (Ru, SiC 쇼트키 다이오드 제작 및 특성평가)

  • 송인복;김형준;나훈주;김대환;정상용;송호근;엄명윤
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.68-68
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    • 2003
  • SiC는 wide bandgap 물질로서 그 material properties로 인하여, high tmperature, high power, high frequency영역으로의 사용이 기대되는 물질이다. 따라서 SiC에 대한 기본적인 연구와 더불어, 그 소자 제작 및 응용에의 연구가 절실한 시점이다. 이에, SiC 기본적인 소자중 하나인 Schottky diode에 대해 연구하였다. 본 논문은 Schottky contact 물질로써 현재까지 연구가 미비한 Ru을 사용하였다. Ru은 Pt 계열물질로써, 다른 metal에 비하여 열역학적으로 안정하며, 또한 그의 산소 화합물인 RuO2는 다른 oxide에 비하여 전도성 이 높은 장점을 가지고 있다. 따라서 Ru-SiC diode는 이러한 측면에서 연구할 만한 가치가 있다.

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Oxidation Characteristics of Methanol on Pt/C and Pt-Ru/C Catalyst for the Anode of Direct Methanol Fuel Cell (Pt/C 및 Pt-Ru/C 촉매를 사용한 직접 메탄올 연료전지 연료극의 메탄올 산화 반응 특성)

  • 정두환;이창형;신동열
    • 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.

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Fabrication and Physical Properties of $RuO_2$ Thin Films ($RuO_2$ 박막의 제조와 물성)

  • 서동주;이재연;김건호
    • Journal of the Korean Vacuum Society
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    • v.3 no.4
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    • pp.442-448
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    • 1994
  • 용액분무법으로 RuO2 박막을 석영 기판위에 성장시켰다. RuO2 박막의 결정구조는 정방 구조이 며 격자상수 a0=4.508 A, c0=3.092 A 이였다. RuO2 박막은 금속성 전도성을 나타냈다. RuO2박마의 광흡 수도는 후열처리함에 따라 증가하였고 박막의 광흡수도의 최소값은 후열처리 온도에 의존하지 않으며 에너지로 환산하면 ∼2.0eV로 거의 일정하였다. RuO2 박막의 후열처리의 온도와 후열처리 분위기가 기 판위에 성장된 RuO2 박막의 표면형태 grain 크기 grain 경계폭 전기적특성등에 영향을 미쳤다. RuO2 박 막이 실험실내의 공기중에 노출됨으로서 시료의 표면에 S와 C가 물리 흡착되었으며 sputtering 시간이 증가함에 따라 Ar+ 이온 빔의 충겨으로 RuO2가 부분적으로 환원되어 O원자의 피크 대 피크 높이가 감 소하여 O/Ru 의피크 높이의 비가 낮게 관측되었다.

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Paper-Electrophoretic Separation of Ruthenium Chloro-Complexes (전기영동에 의한 루테늄 염화착물의 분리)

  • Byung-Hun Lee;Cheon-Hwey Cho
    • Nuclear Engineering and Technology
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    • v.16 no.2
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    • pp.58-63
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    • 1984
  • Paper electrophoretic separation of octahedrally bonded (Ruc $l_{6}$ )$^{3-}$ has been carried out by using the specially designed migration apparatus. The supporting electrolyte solutions are as follows: 0.1M-HCl $O_4$, 0.05 M-HCl+0.09M-KCl, 0.1M-HCl, 5$\times$10$^{-3}$ M-NTA, 0.01M-HCl, 0.01M-HCl $O_4$, 0.01M-citric acid, 0.01M-K $H_2$P $O_4$+0.01M-N $a_2$HP $O_4$, 0.05M-borax, 0.025M-N $a_2$C $O_3$+0.025M-NaHC $O_3$, 0.01M-N $a_3$P $O_4$, 0.01M-NaOH and 0.1 M-NaOH. The (Ruc $l_{6}$ )$^{3-}$ appears in 2 to 4 peaks and is found in several chemical species such as (RuCl ($H_2O$)$_{5}$ )$^{2+}$, cis and trans (RuC $l_2$($H_2O$)$_4$)$^{1+}$, (RuC $l_3$($H_2O$)$_3$)$^{0}$ , (RuC $l_4$($H_2O$)$_2$)$^{1-}$, (RuC $l_{5}$ ($H_2O$))$^{2-}$ and (RuC $l_{6}$ )$^{3-}$. The retention value has been found to be highest in the 0.025M-N $a_2$C $O_3$+0.025M-NaHC $O_3$ electrolyte solution.n.

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Synthesis and Reactions of Organoruthenium(Ⅲ) Complexes (새로운 3가 유기루테늄 착물의 합성과 반응)

  • Lee Dong-Hwan;Kim Hag-Gu;Seo Dae-Ryong;Kim Byung-Soon
    • Journal of the Korean Chemical Society
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    • v.37 no.1
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    • pp.98-104
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    • 1993
  • The paramagnetic organoruthenium(III) complexes $({\eta}^5-C_5Me_5)RuCl_2(PR_3) (PR_3 = PMe_3,\;PEt_3,\;PiPr_3,\;PCy_3,\;PMe_2Ph,\;PMePh_2,\;PPh_3,\;P(p-C_6H_4CH_3)_3$, DPPE, DPPB, Py) (2a∼2k) were synthesized by the reaction of $[({\eta}^5-C_5Me_5)RuCl_2]_2$ (1) with 1 equivalent of the corresponding phosphines $(PR_3)$. The effective magnetic moment ((${\mu}_{eff} = 1.65∼2.07 B.M.$)) derived from the magnetic susceptibility measurements of the complexes (2a∼2k) were consistent with the presence of a "single" unpaired electron in the molecule. Treatment of dichlororuthenium (III) complex ({\eta}^5-C_5Me_5)RuCl_2(PR_3)$ (2) (i) with KBr in acetone afforded the dibromoruthenium (III) complex $({\eta}^5-C_5Me_5)RuBr_2(PR_3) (PR_3 = PPh_3)$, (ii) with sodium amalgam in diethylether led to the bis(phosphine) derivatives $({eta}^5-C_5Me_5)RuCl(PR_3)_2 (PR_3 = PMe_3,\;PMePh_2)$, and (iii) with carbonmonoxide gave to the carbonyl derivatives $({\eta}^5-C_5Me_5)RuCl(PR_3)(CO) (PR_3 = PMe_3,\;PPh_3)$.

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Synthesis and Characterization of a Series of PtRu/C Catalysts for the Electrooxidation of CO (일산화탄소 산화를 위한 PtRu/C 시리즈 촉매의 합성 및 특성 연구)

  • Lee, Seonhwa;Choi, Sung Mook;Kim, Won Bae
    • Clean Technology
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    • v.18 no.4
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    • pp.432-439
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    • 2012
  • The electrocatalytic oxidation of CO was studied using carbon-supported 20 wt% PtRu (PtRu/C) catalysts, which were prepared with different Pt : Ru atomic ratios from 7 : 3 to 3 : 7 using a colloidal method combined with a freeze-drying procedure. The bimetallic PtRu/C catalysts were characterized by various physicochemical analyses, including X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). CO stripping voltammetry measurements indicated that the addition of Ru with a Pt catalyst significantly improved the electrocatalytic activity for CO electrooxidation. Among the tested catalysts, the $Pt_5Ru_5/C$ catalyst had the lowest onset potential (vs.Ag/AgCl) and the largest CO EAS. Structural modification via lattice parameter change and electronic modification in the unfilled d band states for Pt atoms may facilitate the electrooxidation of CO.