• Title, Summary, Keyword: Non-precious Catalyst

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Nitrogen doped graphene/cobalt-based catalyst layers of a PEM fuel cell: Performance evaluation and multi-objective optimization

  • Kazeminasab, Bagher;Rowshanzamir, Soosan;Ghadamian, Hossein
    • Korean Journal of Chemical Engineering
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    • v.34 no.11
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    • pp.2978-2983
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    • 2017
  • The proton exchange membrane fuel cell could be made more commercially viable by substituting the expensive platinic catalyst without loss of performance. This should be done simultaneously through optimization and use of a non-precious metal catalyst. In this study, multi-objective optimization of the catalyst layer was done on nonprecious metal catalysts. Nitrogen-doped graphene (NG)-based cobalt was synthesized as a non-precious metal catalyst. Differential equations were solved at the modeling stage by the shooting method, and objective functions were solved at the optimization stage using sequential quadratic programming. NG-based cobalt was evaluated in a cell and then compared with the platinum catalyst. Results present the synthesized non-precious catalyst as an appropriate replacement for existing precious metal catalyst. Also, the polarization curve demonstrates that the current modeling is in good agreement with NG-based cobalt catalyst. Finally, the Pareto curve at the voltage of 0.6 V (and $300A/m^2$ current density in the base case) indicated that the best tradeoff between cost and performance of the catalyst layer was achieved when the current density was increased in the range of 5% to 15%.

Development of the Direct Borohydride Fuel Cell for Portable Power Source (이동전원용 직접 붕소 연료전지 개발)

  • Yang, Tae-Hyun;Lee, Jung-Woo;Park, Jin-Soo;Lee, Won-Yong;Kim, Chang-Soo
    • New & Renewable Energy
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    • v.3 no.1
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    • pp.68-74
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    • 2007
  • The fuel cells for portable application are attracted using a liquid fuel such as methanol and chemical hydride solutions. Recently, DBFC [Direct Borohydride Fuel Cell] is a candidate for power of portable electronic devices. In this work, the anion exchange membrane and non-precious catalyst for the DBFC were concerned. Anion-exchange membrane was fabricated by amination of polysulfone followed chloromethylation. Non-precious catalysts such as raney-Ni and Ag were used as an anode and cathode catalyst. The optimum conditions of catalyst slurry mixing and MEA fabrication were developed. The single cell performance using anion exchange membrane and non-precious catalyst was evaluated and the results were compared with cation exchange membrane [Nafion membrane] and precious catalysts.

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Heteroatom-doped carbon nanostructures as non-precious cathode catalysts for PEMFC (이종 원자 도핑 탄소 나노재료를 이용한 PEMFC Cathode용 촉매 합성 및 평가)

  • Jo, G.Y.;Shanmugam, S.
    • 한국태양에너지학회:학술대회논문집
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    • pp.406-409
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    • 2012
  • Recently, enormous research efforts have been focused on the development of non-precious catalysts to replace Pt for electrocatalytic oxygen reduction reaction (ORR), and to reduce the cost of proton exchange membrane fuel cells (PEMFCs). In recent years, heteroatom (N, B, and P) doped carbon nanostructures have been received enormous importance as a non-precious electrode materials for oxygen reduction. Doping of foreign atom into carbon is able to modify electronic properties of carbon materials. In this study, nitrogen and boron doped carbon nanostructures were synthesized by using a facile and cost-effective thermal annealing route and prepared nanostructures were used as a non-precious electrocatalysts for the ORR in alkaline electrolyte. The nitrogen doped carbon nanocapsules (NCNCs) exhibited higher activity than that of a commercial Pt/C catalyst, excellent stability and resistance to methanol oxidation. The boron-doped carbon nanostructure (BC) prepared at $900^{\circ}C$ showed higher ORR activity than BCs prepared lower temperature (800, $700^{\circ}C$). The heteroatom doped carbon nanomaterials could be promising candidates as a metal-free catalysts for ORR in the PEMFCs.

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Synthesis and Characterization of Non-precious Metal Co-PANI-C Catalysts for Polymer Electrolyte Membrane Fuel Cell Cathodes (고분자 전해질 연료전지 캐소드용 코발트-폴리아닐린-탄소로 구성된 비귀금속 촉매의 제조 및 특성 평가)

  • Choi, Jong-Ho
    • Journal of the Korean Electrochemical Society
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    • v.16 no.1
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    • pp.52-58
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    • 2013
  • In order to overcome the cost issue for commercialization of polymer electrolyte membrane fuel cell (PEMFC), this research was conducted for replacing platinum cathode catalyst with non-precious metal catalyst. The non-precious metal catalyst (Co-PANI-C) was synthesized by the simple reduction method with polyaniline (PANI), carbon black, and cobalt precursor without any heat treatment. Characterization of new Co-PANI-C composite catalysts was done by the measurement of X-ray diffraction (XRD) and thermogravimetric analysis (TGA) for structure analysis and performed by rotating disk electrode (RDE) and rotating ring disk electrode (RRDE) for electrochemical analysis. As a result, Co-PANI-C catalyst showed 60 mV lower on-set potential for oxygen reduction reaction (ORR) than Pt/C catalyst, but the overall reduction current of Co-PANI-C catalysts by ORR was still smaller than that of Pt/C. In addition, the ORR behavior of Co-PANI-C catalysts depending on the rotation speed of electrode and the stability of Co-PANI-C catalyst under potential cycling and the performance of fuel cell conditions are also discussed.

Recent advances in Studies of the Activity of Non-precious Metal Catalysts for the Oxygen Reduction Reaction in Polymer Electrolyte Membrane Fuel Cells (고분자 전해질 연료전지용 산소환원반응을 위한 비백금촉매의 활성에 대한 최신 연구 동향)

  • Yoon, Ho-Seok;Jung, Won Suk;Choe, Myeong-Ho
    • Journal of the Korean Electrochemical Society
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    • v.23 no.4
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    • pp.90-96
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    • 2020
  • Polymer electrolyte membrane fuel cells, which convert the chemical reaction energy of hydrogen into electric power directly, are a type of eco-friendly power for future vehicles. Due to the sluggish oxygen reduction reaction and costly Pt catalyst in the cathode, the research related to the replacement of Pt-based catalysts has been vitally carried out. In this case, however, the performance is significantly different from each other and a variety of factors have existed. In this review paper, we rearrange and summarize relevant papers published within 5 years approximately. The selection of precursors, synthesis method, and co-catalyst are represented as a core factor, while the necessity of research for the further enhancement of activity may be raised. It can be anticipated to contribute to the replacement of precious metal catalysts in the various fields of study. The final objective of the future research is depicted in detail.

Optimal Metal Dose of Alternative Cathode Catalyst Considering Organic Substances in Single Chamber Microbial Fuel Cells

  • Nam, Joo-Youn;Moon, Chungman;Jeong, Emma;Lee, Won-Tae;Shin, Hang-Sik;Kim, Hyun-Woo
    • Environmental Engineering Research
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    • v.18 no.3
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    • pp.145-150
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    • 2013
  • Optimal preparation guidelines of a cathode catalyst layer by non-precious metal catalysts were evaluated based on electrochemical performance in single-chamber microbial fuel cells (MFCs). Experiments for catalyst loading rate revealed that iron(II) phthalocyanine (FePc) can be a promising alternative, comparable to platinum (Pt) and cobalt tetramethoxyphenylporphyrin (CoTMPP), including effects of substrate concentration. Results showed that using an optimal FePc loading of $1mg/cm^2$ was equivalent to a Pt loading of $0.35mg/cm^2$ on the basis of maximum power density. Given higher loading rates or substrate concentrations, FePc proved to be a better alternative for Pt than CoTMPP. Under the optimal loading rate, it was further revealed that 40 wt% of FePc to carbon support allowed for the best power generation. These results suggest that proper control of the non-precious metal catalyst layer and substrate concentration are highly interrelated, and reveal how those combinations promote the economic power generation of single-chamber MFCs.

Development of cobalt encased in nitrogen and sulfur co-doped carbon nanotube for non-precious metal catalyst toward oxygen reduction reaction

  • Kim, Tae-Hyun;Sang, Byoung-In;Yi, Sung-Chul
    • Journal of Ceramic Processing Research
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    • v.19 no.6
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    • pp.499-503
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    • 2018
  • In this paper, cobalt embedded in nitrogen and sulfur co-doped carbon nanotubes (CoNSTs) were synthesized for oxygen reduction reaction (ORR) catalysts. The CoNSTs were prepared through a facile heat treatment method without any templates. Different amounts of the metal salt were employed to examine the physicochemical and electrochemical properties of the CoNSTs. The CoNSTs showed the bamboo-like tube morphology with the encased Co nanoparticles in the tubes. Through the x-ray photoelectron spectroscopy analysis, the catalysts exhibited different chemical states of the nitrogen and sulfur species. As a result, the CoNST performed high activity toward the ORR in an acidic condition with the onset potential of 0.863 V (vs. reversible hydrogen electrode). It was clearly demonstrated from the electrochemical characterizations that the quality of the nitrogen and sulfur species significantly influences the ORR activity rather than the total amount of the dopants.

The effects of conductivity and CNT cathode on electricity generation in air-cathode microbial fuel cell (공기양극 미생물연료전지 시스템에서 전력발생특성에 미치는 전기전도도와 CNT 양극의 영향)

  • Yoo, Kyu-Seon;Park, Hyun-Soo;Song, Young-Chae;Woo, Jung-Hui;Lee, Chae-Young;Chung, Jae-Woo
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.3
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    • pp.355-360
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    • 2012
  • The characteristics of power generation were investigated by changing the electrical conductivity from 10 to 40mS/cm using air-cathode microbial fuel cell, which had graphite fiber fabric(GFF) anode. There were three kinds of cathode used: one was carbon cloth cathode coated with Pt, another was carbon nanotube(CNT) cathode with non-precious catalyst of Fe-Cu-Mn, and the other was carbon nanotube(CNT) cathode without any catalyst. When it was operated in batch mode, power density of 1369.5mW/$m^2$ was achieved at conductivity of 20mS/cm. Power density from MFC with CNT cathode coated with multi-catalyst of Fe-Cu-Mn was shown about 985.55mW/$m^2$, which was 75.1% compared the power density of carbon cloth coated with Pt. This meant that CNT cathode coated with multi-catalyst of Fe-Cu-Mn could be an alternative of carbon cloth cathode.

Photocatalytic degradation and antibacterial investigation of nano synthesized Ag3VO4 particles @PAN nanofibers

  • Saud, Prem Singh;Ghouri, Zafar Khan;Pant, Bishweshwar;An, Taehee;Lee, Joong Hee;Park, Mira;Kim, Hak-Yong
    • Carbon letters
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    • v.18
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    • pp.30-36
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    • 2016
  • Well-dispersed Ag3VO4 nanoparticles @polyacrylonitrile (PAN) nanofibers were synthesized by an easily controlled, template-free method as a photo-catalyst for the degradation of methylene blue. Their structural, optical, and photocatalytic properties have been studied by X-ray diffraction, transmission electron microscopy, field-emission scanning electron microscopy equipped with rapid energy dispersive analysis of X-ray, photoluminescence, and ultraviolet-visible spectroscopy. The characterization procedures revealed that the obtained material is PAN nanofibers decorated by Ag3VO4 nanoparticles. Photocatalytic degradation of methylene blue investigated in an aqueous solution under irradiation showed 99% degradation of the dye within 75 min. Finally, the antibacterial performance of Ag3VO4 nanoparticles @PAN composite nanofibers was experimentally verified by the destruction of Escherichia coli. These results suggest that the developed inexpensive and functional nanomaterials can serve as a non-precious catalyst for environmental applications.

Wet air oxidation of paracetamol over precious metal/Ti mesh monolith catalyst

  • Szabados, Erika;Sagi, Gyuri;Somodi, Ferenc;Maroti, Boglarka;Sranko, David;Tungler, Antal
    • Journal of Industrial and Engineering Chemistry
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    • v.46
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    • pp.364-372
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    • 2017
  • The catalytic wet oxidation of paracetamol (PAR) was tested with Pt, Ru, Ir containing Ti monoliths measuring COD, TOC and TN conversion and compared with that of the non-catalytic reaction. The decrease of PAR concentration during reaction was followed by UV-vis spectrometry also. The catalysts were characterized by XPS, PGAA, TPR and SEM-EDX. The monometallic Pt and Ru/Ti catalysts were the most active, even below $150^{\circ}C$. $RuO_2/Ti$ had the highest specific activity. After 100 h reaction time the Pt loss was 23%, while the $RuO_2/Ti$ kept its Ru content. The $RuO_2/TiO_2$ composite formation explains the highest activity and stability.