• Title/Summary/Keyword: Nanocatalyst

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

  • JAEYOUNG LEE;HONGKI LEE
    • Journal of Hydrogen and New Energy
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    • v.34 no.5
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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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    • v.34 no.5
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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.

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

  • JAEYOUNG LEE;HONGKI LEE
    • Journal of Hydrogen and New Energy
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    • v.35 no.2
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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.

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

  • Kim, Sang Hoon
    • Applied Chemistry for Engineering
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    • v.25 no.4
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    • pp.341-345
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    • 2014
  • Catalyst nanoparticles are prepared by arc plasma deposition (APD). First, overview of the APD technique is reviewed and second, some applications of the technique for nanocatalyst preparation are reviewed. Nanoparticles prepared by APD are typically 1~5 nm in size and their catalytic activity is generally better than that of conventional wet-chemically prepared nanocatalysts.

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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    • v.27
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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.

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

  • Jang, Ji-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.35 no.1
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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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    • v.61 no.2
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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.

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

  • DAI, GUANXIA;LU, LIXIN;LEE, JAEYOUNG;LEE, HONGKI
    • Journal of Hydrogen and New Energy
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    • v.32 no.5
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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.