• 제목/요약/키워드: mixed catalyst

검색결과 233건 처리시간 0.025초

플라즈마 에칭 및 $PdCl_2/SnCl_2$ 촉매조건이 무전해 동도금 피막의 성능에 미치는 영향 (Effect of Plasma Etching and $PdCl_2/SnCl_2$ Catalyzation on the Performance of Electroless Plated Copper Layer)

  • 오경화;김동준;김성훈
    • 한국의류학회지
    • /
    • 제27권7호
    • /
    • pp.843-850
    • /
    • 2003
  • Cu/PET film composites were prepared by electroless copper plating method. In order to improve adhesion between electroless plated Cu layer and polyester (PET) film, the effect of pretreatment conditions such as etching method, mixed catalyst composition were investigated. Chemical etching and plasma treatment increased surface roughness in decreasing order of Ar>HCl>O$_2$>NH$_3$. However, adhesion of Cu layer on PET film increased in the following order: $O_2$<Ar<HCl<NH$_3$. It indicated that appropriate surface roughness and introduction of affinitive functional group with Pd were key factors of improving adhesion of Cu layer. PET film was more finely etched by HCI tolution, resulting in an improvement in adhesion between Cu layer and PET film. Plasma treatment with NH$_3$produced nitrogen atoms on PET film, which enhances chemisorption of Pd$^{2+}$ on PET film, resulting in improved adhesion and shielding effectiveness of Cu layer deposited on the Pd catalyzed surface. Surface morphology of Cu plated PET film revealed that Pd/Sn colloidal particles became more evenly distributed in the smaller size by increasing the molar ratio of PdCl$_2$; SnCl$_2$from 1 : 4 to 1 : 16. With increasing the molar ratio of mixed catalyst, adhesion and shielding effectiveness of Cu plated PET film were increased.d.

Preparation of Platinum catalysts for PEM Fuel cells

  • Sasikumar G.;Ryu H.
    • 한국전기화학회:학술대회논문집
    • /
    • 한국전기화학회 2003년도 연료전지심포지움 2003논문집
    • /
    • pp.189-192
    • /
    • 2003
  • In this work, we have prepared platinum catalyst by various methods, investigated fuel cell performance and compared performance with commercially available $20\%$ Pt supported on carbon (Pt/C) catalyst. We have found that Pt/C prepared by reduction of chloroplatinic acid in mixed solvent (water+ethylene glycol) gives better performance compared to that produced by reduction of aqueous chloroplatinic acid, which can be attributed to smaller catalyst particle size and lower agglomeration in the mixed solvent. We have also prepared a novel platinum electrocatalyst by depositing platinum on Nafion coated carbon powder and it shows great promise. The performance of electrode prepared using $20\%Pt$ onn Nafion coated carbon mixed with Pt/C was found to be higher than the performance of electrodes using commercially available $20\%$ Pt/C, up to a current density of about $1100mA/cm^2$. The cell voltages obtained were respectively 621 and 603mV, at a current density of: $1000mA/cm^2$, in a single cell using $0.25mgPt/cm^2$ and Nafion 10035 membrane at $80^{\circ}C$ using hydrogen/oxygen reactants at 1 atm pressure.

  • PDF

합성가스 제조를 위한 CO2/수증기에 의한 메탄 개질반응 연구 (The Study on Methane Reforming by CO2 and Steam for Manufacture of Synthesis Gas)

  • 조원일;이승호;모용기;신동근;백영순
    • 한국수소및신에너지학회논문집
    • /
    • 제15권4호
    • /
    • pp.301-308
    • /
    • 2004
  • The methane reforming with $CO_2$ and steam for manufacture of synthesis gas over $Ni/ZrO_2$ catalyst was investigated. Mixed reforming carried out $CO_2$ dry reforming with $O_2$ and steam for development of DME process in pilot plant. To improve a catalyst deactivation by coke formation, the mixed reforming added carbon dioxide and steam as a oxidizer of the methane reforming was suggested. The result of experiments over commercial catalyst in $CO_2$ dry reforming has shown that the catalyst activity decrease rapidly after 20 hours. In case of $NiO-MgO/Al_2O_3$ catalyst, the deactivation of 20 percent after 30 hours was occurred. The activity of Ni/C catalyst still was not decreased dramatically after 100 hours. The effect of $H_2$ reforming with steam over $Ni/CO_2$ catalyst obtained the optimal conversion of methane and carbon dioxide, and could be produced synthesis gas at ratio of $H_2/CO$ under 1.5.

Studies on the Polycondensation Rate of Poly(ethylene 2,6-naphthalate). 2. Polycondensation by Antimony Catalysts

  • 박상순;임승순
    • Bulletin of the Korean Chemical Society
    • /
    • 제16권11호
    • /
    • pp.1099-1104
    • /
    • 1995
  • The catalyzed polycondensations of bis(2-hydroxyethyl) naphthalate were kinetically investigated in the presence of various antimony compounds as a catalyst. The polymerization were investigated with various ligand types of antimony oxides, various concentrations of antimony triacetate and titanium/antimony mixed catalysts. The time to reach the maximum molecular weight was remarkably changed in each case. With increasing the concentration of antimony acetate, the propagation rate was largely increased, while the degradation rate was slightly decreased. It also can be seen that the propagation and degradation rate were larger influenced by the equimolecular titanium/antimony mixed catalyst than other mixed catalysts. The temperature dependence of bis(2-hydroxyethyl) naphthalate with antimony triacetate also has been studied. From the results, it was found that the propagation rate was less influenced by a temperature change than the degradation rate.

층상 혼합금속산화물 촉매에 의한 $N_2O$ 분해에서 Ceria 첨가 및 CO 환원제의 영향 (Effects of Ceria and CO Reductant on $N_2O$ Decomposition over the Layered Mixed Oxide Catalysts)

  • 양기선;장길상
    • 청정기술
    • /
    • 제16권4호
    • /
    • pp.284-291
    • /
    • 2010
  • 온실가스로 알려진 $N_2O$의 촉매 분해는 최소한 670 K 이상의 온도가 요구되는 난해한 공정으로 알려져 있다. 본 연구는 CO 환원제와 더불어 473 K의 저온에서도 $N_2O$를 전량 분해될 정도로 높은 활성을 나타내는 혼합금속산화물(mixed metal oxide: MMO) 촉매에 Ce을 첨가함으로서 나타나는 $N_2O$ 분해활성에의 영향을 검토하기 위하여 수행되었다. MMO 촉매는 Co 및 Al 외에 Rh과 Pd을 사용하고, 여기에 Ce을 미량 첨가하여 공침전법으로 제조하였으며, 결과적으로 Ce 함량이 증가함에 따라 촉매 표면적은 감소하고 $N_2O$의 직접분해 활성이 감소하는 현상이 나타났다. 그러나 CO 환원제의 분위기 하에서는 이러한 활성 감소를 상쇄하고도 남을 정도의 높은 $N_2O$ 분해활성을 나타냈으며 Ce 첨가비율에 따른 활성저하도 줄일 수 있어서 MMO 촉매의 물리적 안정성 증대를 위해 Ce을 첨가할 경우 CO 환원제에 의한 $N_2O$ 환원 반응계의 활성 안정성도 유지될 수 있는 것으로 확인되었다.

필름형 혼합폐플라스틱의 열분해로부터 얻은 왁스오일의 고급화연구 - 촉매 양과 반응온도의 영향 - (A Study of Upgrading Wax Oil Obtained from Pyrolysis of Mixed Plastic Waste with Film Type - The Influence of Catalyst Amount and Reaction Temperature)

  • 이경환;송광섭;남기윤
    • 신재생에너지
    • /
    • 제5권4호
    • /
    • pp.52-58
    • /
    • 2009
  • Upgrading of pyrolysis wax oil using HZSM-5 catalyst has been conducted in a continuous fixed bed reactor at $450^{\circ}C$, 1hour, LHSV 3.5/h. The catalytic degradation was studied with a function of catalyst amount and reaction temperature. The raw pyrolysis wax oil shows relatively high boiling point distribution ranging from around $300^{\circ}C$ to $550^{\circ}C$, which has considerably higher boiling point distribution than that of commercial diesel. The catalytic degradation using HZSM-5 catalyst shows the high conversion of pyrolysis wax oil to light hydrocarbons. The liquid product obtained shows high gasoline range fraction as around 90% fraction and considerably high aromatic fraction in liquid product. Here, the experimental variable such as catalyst amount and reaction temperature was influenced on the product distribution.

  • PDF

메탄의 부분산화를 이용한 이중 혼합금속산화물 촉매 반응시스템의 N2O 분해 특성 연구 (N2O Decomposition Characteristics of Dual Bed Mixed Metal Oxide Catalytic System using Partial Oxidation of Methane)

  • 이난영;우제완
    • Korean Chemical Engineering Research
    • /
    • 제46권1호
    • /
    • pp.82-87
    • /
    • 2008
  • Methane의 부분산화에 의하여 일산화탄소를 발생시키고 이를 이용하여 온실가스로 알려져 있는 $N_2O$를 분해시키기 위한 이중 촉매 반응시스템의 반응 특성을 살펴보았다. 일산화탄소를 발생시키기 위한 제1 반응기의 조건은 Co-Rh-Al (1/0.2/1) 촉매를 사용할 때 $500^{\circ}C$의 온도에서 methane과 산소의 비율이 5:1이고 GHSV $8,000h^{-1}$ 일때 가장 적합하였다. 제1 반응기에서 methane을 부분산화시켜 얻은 혼합 가스를 사용하는 이중 반응시스템에서 제2 반응기에 촉매로 Co-Rh-Al(1/0.2/1)과 Co-Rh-Zr-Al(1/0.2/0.3/1)을 사용한 경우 Co-Rh-Al(1/0.2/1) 촉매를 사용한 single bed system 보다 $250^{\circ}C$ 이하의 저온에서 우수한 분해성능을 나타내었다. 두 경우 모두 $250^{\circ}C$ 이상의 온도에서는 $N_2O$가 100% 분해되었다. 또한, 제2 반응기에서 $N_2O$ 분해성능은 NO의 존재 유무에 관계없이 산소의 농도가 증가할수록 감소함을 보여주었다. 다만 NO가 존재할 경우 산소의 농도가 10,000 ppm 이하일 때 100% 분해율을 보이며 그 이상일 경우 급격히 감소하였다.

광촉매제를 사용한 콘크리트 보도블록의 제조 및 특성 (Manufacture and Characteristics of Concrete Sidewalk Blocks Using Photocatalyst Agent)

  • 정용욱;장준호;김종규
    • 한국건설순환자원학회논문집
    • /
    • 제7권4호
    • /
    • pp.423-430
    • /
    • 2019
  • 본 연구에서는 콘크리트 보도블록의 표층에 광촉매를 적용하여 광촉매 혼입률 및 블록 표면워싱 유무 등에 따른 휨강도, 흡수율, 메틸렌블루 광촉매 분해 성능 및 방오성능을 평가하였다. 실험결과, 콘크리트 블록 표면층에만 광촉매를 혼입한 블록의 휨강도는 광촉매 무혼입인 기준콘크리트 블록의 휨강도 5.46MPa과 비교하여 광촉매 5% 혼입 일반블록(SNW) 5.32MPa로 나타났으며, 표면워싱블록(SW) 5.26MPa, 광촉매 10%혼입 일반블록(SNW) 5.26MPa, 표면워싱블록(SW) 5.15MPa로 나타나 콘크리트 블록의 표면 워싱 유무 및 광촉매 혼입율이 휨강도에 미치는 영향은 없는 것으로 나타났다. 또한 콘크리트 보도블록의 광촉매 분해성능은 이산화티타늄이 5% 혼합된 시편의 메틸렌블루 제거율은 34.2%, 이산화티타늄이 10% 혼합된 시편의 메틸렌블루 제거율은 37.1%, 세척을 실시한 경우 이산화티타늄이 5% 혼합된 시편의 경우 제거율은 약 37.9%, 10% 혼합된 시편의 메틸렌블루 제거율은 약 37.6%로 나타났다.

$Al_2O_3$ 지지 CaO촉매에 의한 식물유와 혼합지방의 바이오디젤화 (Conversion of Vegetable Oils and Mixed Fat into Biodiesel Using $Al_2O_3$-Supported CaO Catalyst)

  • 현영진
    • 한국응용과학기술학회지
    • /
    • 제27권4호
    • /
    • pp.421-426
    • /
    • 2010
  • The transesterification of rapeseed oil, soybean oil, and mixed fat were conducted at $65^{\circ}C$ with $Al_2O_3$-supported CaO, 0.8 wt% KOH, 1 wt% NaOH and mixed catalyst. The overall conversion(%) of rapeseed oil indicated to be 96% at the 12:1 molar ratio of methanol to oil, 8 wt% CaO and 2 wt% water. The pH ranges of biodiesel for mixed fat using four catalysts and for three fats using 8wt% CaO were 7.3-9.1, 7.3-7.5, respectively. The volumes of water needed to wash biodiesel from rapeseed oil using 0.8 wt% KOH and 8 wt% CaO were 15 mL and 3 mL.

4성분계 복합 산화물 촉매 이용 메탄의 부분산화에 의한 메탄올 직접 합성 (Direct Methanol Synthesis by Partial Oxidation of Methane over Four-component Mixed Oxide Catalysts)

  • 김영국;이광혁;함현식
    • 한국응용과학기술학회지
    • /
    • 제31권3호
    • /
    • pp.446-452
    • /
    • 2014
  • Methanol was directly produced by the partial oxidation of methane with four-component mixed oxide catalysts. Four-component(Mo-Bi-Cr-Si) mixed oxide catalysts were prepared by the co-precipitation and sol-gel methods. The catalyst prepared by the sol-gel method showed about eleven times higher surface area than that prepared by the co-precipitation method. From the $O_2$-TPD experiment of the prepared catalysts, it was proven that there exists two types of oxygen species, and the oxygen species that participates in the partial oxidation reaction is the lattice oxygen desorbing around $750^{\circ}C$. The optimum reaction condition for methanol production was $420^{\circ}C$, 50 bar, flow rate of 115 mL/min, and $CH_4/O_2$ ratio of 10/1.5, providing methane conversion and methanol selectivity of 3.2 and 26.7%, respectively.