• Title/Summary/Keyword: Pd catalyst

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Preparation of Graphene-Palladium Composite by Aerosol Process and It's Characterization for Glucose Biosensor (에어로졸 공정에 의한 그래핀-팔라듐 복합체 제조 및 글루코스 바이오센서 특성평가)

  • Kim, Sun Kyung;Jang, Hee Dong;Chang, Hankwon;Choi, Jeong-Woo
    • Particle and aerosol research
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    • v.10 no.2
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    • pp.53-59
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    • 2014
  • Palladium (Pd) nanoparticles attached graphene (GR) composite was synthesized for an enhanced glucose biosensor. Aerosol spray pyrolysis (ASP) was employed to synthesize the GR-Pd composite using a colloidal mixture of graphene oxide (GO) and palladium chloride ($PdCl_2$) precursor. The effects of the weight ratio of the Pd/GR on the particle properties including the morphology and crystal structure were investigated. The morphology of GR-Pd composites was generally the shape of a crumpled paper ball, and the average composite size was about $1{\mu}m$. Pd nanoparticles less than 20 nm in diameter were deposited on GR sheets and the Pd nanoparticles showed clear crystallinity. The characteristic of the glucose biosensor fabricated with the as-prepared GR-Pd composite was tested through cyclic voltammetry measurements. The biosensor exhibited a high current flow as well as clear redox peaks, which resulted in a superior ability of the catalyst in terms of an electrochemical reaction. The highest sensitivity obtained from the amperometric response of the glucose biosensor was $14.4{\mu}A/mM{\cdot}cm^2$.

Propane Dehydrogenation over a Hydrogen Permselective Membrane Reactor

  • Chang, Jong-San;Roh, Hyun-Seog;Park, Min-Seok;Park, Sang-Eon
    • Bulletin of the Korean Chemical Society
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    • v.23 no.5
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    • pp.674-678
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    • 2002
  • The dehydrogenation of propane to propylene has been studied in an isothermal high-temperature shell-and-tube membrane reactor containing a Pd-coated ${\psi}$-Al2O3 membrane and a Pt/K/Sn/Al2O3 packed catalyst . A tubular Pd-coated ${\psi}$-Al2O3 membrane was prepared by an electroless plating method. This membrane showed high hydrogen to nitrogen permselectivities (PH2N2 = 10-50) at 400 $^{\circ}C$ and 500 $^{\circ}C$ with various transmembrane pressure drops. The employment of a membrane reactor in the dehydrogenation reaction, which selectively separates hydrogen from the reaction mixture along the reaction path, can greatly increase the conversion and enable operation of the reactor at lower temperatures. High hydrogen permselectivity has been confirmed as a key factor in determining the reactor performance of conversion enhancement.

Stability and catalytic activity of Pd catalyst for electroless plating. (무전해 도금용 팔라듐 촉매 용액의 안정성 및 촉매활성)

  • Kim, Dong-Hyeon;Choe, Hye-Gang;Yu, Gyeong-Jin;Lee, Seong-Jun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2016.11a
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    • pp.200.2-200.2
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    • 2016
  • 무전해 도금용 팔라듐 촉매액 중의 팔라듐 이온과 주석이온의 농도비($Sn^{2+}/Pd^{2+}$), 염산의 농도 및 첨가제의 농도 등은 촉매액의 안정성 및 흡착력에 영향을 미치는 것으로 알려져 있다. 무전해 도금용 콜로이드 타입 팔라듐 촉매액에 요구되어지는 특성으로는 1) 액 안정성이 양호하여 장시간 연속 사용에 있어서 나노입자의 응집 및 침전이 없을 것 2) 피도금체 표면에 흡착력이 양호할 것 3) 촉매활성이 충분하여 다음 공정인 무전해 도금피막의 초기석출성이 양호할 것 등이다. 본 연구에서는, 콜로이드 타입 팔라듐 촉매액 중의 염산 농도 및 금속이온의 농도비($Sn^{2+}/Pd^{2+}$), 첨가제를 변화시켜 촉매액의 안정성 및 촉매활성에 미치는 영향을 조사하였다. 그 결과를 시판의 팔라듐 촉매액과 비교하여 보고한다.

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Tin-Free Three-Component Coupling Reaction of Aryl Halides, Norbornadiene (or Norbornene), and Alkynols Using a Palladium Catalyst

  • Choi, Cheol-Kyu;Hong, Jin-Who;Tomita, Ikuyoshi;Endo, Takeshi
    • Bulletin of the Korean Chemical Society
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    • v.23 no.1
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    • pp.112-118
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    • 2002
  • Good-to-excellent yields of 2,3-Disubstituted norbornenes (or norbornanes) were obtained using a Pd/Cu catalyzed three-component ternary coupling reaction of aryl halides, norbornadiene (or norbornene), and alkynols in toluene at $100{\circ}C$ in the presence of 5.5 M NaOH as a base and benzyltriethylammonium chloride as a phase transfer catalyst. The results of experiments using various aromatic halides suggest that the ternary coupling reaction is promoted by bromide.

Recent Research Progress on the Atomic Layer Deposition of Noble Metal Catalysts for Polymer Electrolyte Membrane Fuel Cell (고분자 전해질 연료전지용 촉매 소재 개발을 위한 원자층증착법 연구 동향)

  • Han, Jeong Hwan
    • Journal of Powder Materials
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    • v.27 no.1
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    • pp.63-71
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    • 2020
  • It is necessary to fabricate uniformly dispersed nanoscale catalyst materials with high activity and long-term stability for polymer electrolyte membrane fuel cells with excellent electrochemical characteristics of the oxygen reduction reaction and hydrogen oxidation reaction. Platinum is known as the best noble metal catalyst for polymer electrolyte membrane fuel cells because of its excellent catalytic activity. However, given that Pt is expensive, considerable efforts have been made to reduce the amount of Pt loading for both anode and cathode catalysts. Meanwhile, the atomic layer deposition (ALD) method shows excellent uniformity and precise particle size controllability over the three-dimensional structure. The research progress on noble metal ALD, such as Pt, Ru, Pd, and various metal alloys, is presented in this review. ALD technology enables the development of polymer electrolyte membrane fuel cells with excellent reactivity and durability.