• 제목/요약/키워드: Nanocatalyst

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음이온 교환막 수전해용 Fe-Ni-Pt 나노촉매 제조 및 특성 (Preparation and Characterization of Fe-Ni-Pt Nanocatalyst for Anion Exchange Membrane in Alkaline Electrolysis)

  • 이재영;이홍기
    • 한국수소및신에너지학회논문집
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    • 제34권5호
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    • pp.421-430
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    • 2023
  • Fe-Ni-Pt nanocatalysts were loaded on carbon black powders which were synthesized by a spontaneous reduction reaction of iron (II) acetylacetonate, nickel (II) acetylacetonate and platinum (II) acetylacetonate. The morphology and the loading weight of Fe-Ni-Pt nanoparticles were characterized by transmission electron microscopy and thermogravimetric analyzer. The amount of Fe-Ni-Pt catalyst supported on the carbon black surface was about 6.42-9.28 wt%, and the higher the Fe content and the lower the Pt content, the higher the total amount of the metal catalyst supported. The Brunauer-Emmett-Teller Analysis (BET) specific surface area of carbon black itself without metal nanoparticles supported was 233.9 m2/g, and when metal nanoparticles were introduced, the specific surface area value was greatly reduced. This is because the metal nanocatalyst particles block the pore entrance of the carbon black, and thereby the catalytic activity of the metal catalysts generated inside the pores is reduced. From the I-V curves, as the content of the Pt nanocatalyst increased, the electrolytic properties of water increased, and the activity of the metal nanocatalyst was in the order of Pt > Ni > Fe.

Heterogeneous Suzuki Cross-Coupling Reaction Catalyzed by Magnetically Recyclable Nanocatalyst

  • Choi, Kwang-Hyun;Shokouhimehr, Mohammadreza;Sung, Yung-Eun
    • Bulletin of the Korean Chemical Society
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    • 제34권5호
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    • pp.1477-1480
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    • 2013
  • The Suzuki cross-coupling reactions proceeded in excellent yields when it was catalyzed by magnetically recyclable nanocatalyst. This nanocatalyst provided very high catalytic activity with low loading level (1 mol %), because the palladium nanoparticles were so small in size (~2 nm) and located on the surface of the nanocomposite. It was also easily recovered from the reaction mixture using a magnet and reused for six consecutive cycles.

건식 공정에서 자발적 환원 반응에 의한 AEM 수전해용 Fe-Ni 나노 촉매 제조 및 특성 (Preparation and Characterization of Fe-Ni Nanocatalyst for AEM Electrolysis via Spontaneous Reduction Reaction in Dry Process)

  • 이재영;이홍기
    • 한국수소및신에너지학회논문집
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    • 제35권2호
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    • pp.185-194
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    • 2024
  • Fe-Ni nanocatalysts loaded on carbon black were prepared via spontaneous reduction reaction of iron (II) acetylacetonate and nickel (II) acetylacetonate in dry process. Their morphology and elemental analysis were characterized by scanning electron microscopy, transmission electron microscopy (TEM), and energy dispersive X-ray analyzer. The loading weight of the nanocatalysts was measured by thermogravimetric analyze and the surface area was measured by BET analysis. TEM observation showed that Fe and Ni nanoparticles was well dispersed on the carbon black and their average particle size was 4.82 nm. The loading weight of Fe-Ni nanocatalysts on the carbon black was 6.83-7.32 wt%, and the value increased with increasing iron (II) acetylacetonate content. As the Fe-Ni loading weight increased, the specific surface area decreased significantly by more than 50%, because Fe-Ni nanoparticles block the micropores of carbon black. I-V characteristics showed that water electrolysis performance increased with increasing Ni nanocatalyst content.

아크플라즈마 증착을 이용한 나노촉매 재료 제작 (Nanocatalyst Materials Prepared by Arc Plasma Deposition)

  • 김상훈
    • 공업화학
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    • 제25권4호
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    • pp.341-345
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    • 2014
  • 아크플라즈마를 이용해 촉매입자를 촉매지지체에 건식으로 직접 분산하는 기술에 대한 개괄과 응용사례를 소개한다. 이 방법은 촉매입자를 담지하는 일반적인 방법인 습식법의 단점을 개선하고자 촉매입자를 기화하여 직접 담지체에 증착하는 방법이다. 아크플라즈마 증착을 이용해 제작한 촉매재료의 성능을 연구한 사례 세가지를 소개한다. 이 사례들을 통해 이 방법으로 증착되는 나노입자의 크기가 1~5 nm 정도이고 일반적으로 습식 방법보다 촉매성능면에서 우수한 성능을 나타낸다는 것을 보인다.

Surface modification of graphene oxide by citric acid and its application as a heterogeneous nanocatalyst in organic condensation reaction

  • Maleki, Ali;Hajizadeh, Zoleikha;Abbasi, Hamid
    • Carbon letters
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    • 제27권
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    • pp.42-49
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    • 2018
  • A citric acid functionalized graphene oxide nanocomposite was successfully synthesized and the structure and morphology of the nanocatalyst were comprehensively characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis, X-ray diffraction patterns, atomic force microscopy images, scanning electron microscopy images, transmission electron microscopy images, and thermogravimetric analysis. The application of this nanocatalyst was exemplified in an important condensation reaction to give imidazole derivatives in high yields and short reaction times at room temperature. The catalyst shows high catalytic activity and could be reused after simple work up and easy purification for at least six cycles without significant loss of activity, which indicates efficient immobilizing of citrate groups on the surface of graphene oxide sheets.

저항변화식 가스센서 선택성 향상을 위한 멤브레인 및 촉매 연구동향 (Research Progress in Membrane and Catalyst for Highly Selective Chemiresistive Gas Sensors)

  • 장지수
    • 한국전기전자재료학회논문지
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    • 제35권1호
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    • pp.11-17
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    • 2022
  • Direct exposure to toxic and hazardous gases has always been considered as the most pervasive problem worldwide, leading to a gradual increase in the number of asthma patients due to NOx/SOx gases inhaling and exposure to 50 ppm formaldehyde gases. Therefore, the development of accurate gas sensors is a key issue for resolving these problems. To address such issues, the development of membranes for selective filtering of target molecules as well as nanocatalyst for enhancing the sensing selectivity is highly crucial. In this review, the research progress for porous membrane materials (e.g. MOFs, and graphene) and nanocatalyst technology for the development of selective and accurate gas sensors will be discussed.

Improved Kerosene Quality with the Use of a Gamma Alumina Nanoparticles Supported Zinc Oxide Catalyst in a Digital Batch Baffled Reactor: Experiments and Process Modelling

  • Jasim I. Humadi;Ghassan Hassan Abdul Razzaq;Ghassan Hassan Abdul Razzaq;Mustafa A. Ahmed;Liqaa I. Saeed
    • Korean Chemical Engineering Research
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    • 제61권2호
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    • pp.226-233
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    • 2023
  • To create an environmentally sustainable fuel with a low sulfur concentration, requires alternative sulfur removal methods. During the course of this study, a high surface gamma alumina-supported ZnO nanocatalyst with a ZnO/-Al2O3 ratio of 12% was developed and tested for its ability to improve the activity of the oxidative desulfurization (ODS) process for the desulfurization of kerosene fuel. Scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) were used to characterize the produced nanocatalyst. In a digital batch baffled reactor (20~80 min), the effectiveness of the synthesized nanocatalyst was tested at different initial concentrations of dibenzothiophene (DBT) of 300~600 ppm, oxidation temperatures (25~70 ℃), and oxidation periods (0.5, 1, and 2 hours). The baffles included in the digital baffled batch reactor resist the swirling of the reaction mixture, thus facilitating mixing. The ODS procedure yielded the maximum DBT conversion (95.5%) at 70 ℃ with an 80-minute reaction time and an initial DBT level of 600 ppm. The most precise values of kinetic variables were subsequently determined using a mathematical modelling procedure for the ODS procedure. The average absolute error of the simulation findings was less than 5%, demonstrating a good degree of agreement with the experimental results acquired from all runs. The optimization of the operating conditions revealed that 99.1% of the DBT can be removed in 140 minutes.

친핵성 용매 중에서 자발적 환원반응에 의한 음이온 교환막 수전해용 Fe/Ni 나노 촉매의 제조 및 특성 (Preparation and Characterization of Fe/Ni Nanocatalyst in a Nucleophilic Solvent for Anion Exchange Membrane in Alkaline Electrolysis)

  • 대관하;노립신;이재영;이홍기
    • 한국수소및신에너지학회논문집
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    • 제32권5호
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    • pp.293-298
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    • 2021
  • To synthesize Fe/Ni nanocatalysts loaded on carbon black, Iron(II) acetylacetonate and nickel (II) acetylacetonate and were reduced to Fe and Ni metallic nanoparticles by a spontaneous reduction reaction. The distribution of the Fe and Ni nanoparticles was observed by transmission electron microscopy, and the loading weight of Fe/Ni nanocatalysts on the carbon black was measured by thermogravimetric analyzer. The elemental ratio of Fe and Ni was estimated by energy dispersive x-ray analyzer. It was found that the loading weight of Fe/Ni nanoparticles was 6.23 wt%, and the elemental ratio of Fe and Ni was 0.53:0.40. Specific surface area was measured by BET analysis instrument and I-V characteristics were estimated.