• Title, Summary, Keyword: metal catalyst

Search Result 751, Processing Time 0.058 seconds

Catalytic Activity of Commercial Metal Catalysts on the Combustion of Low-concentration Methane (저농도 메탄 연소에서 상용 금속촉매의 활성)

  • Lee Kyong-Hwan;Park Jae-Hyun;Song Kwang-Sup
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.21 no.6
    • /
    • pp.625-630
    • /
    • 2005
  • This study was focused on the catalytic activity for the combustion of low-concentration methane using various commerical catalysts (six transition metal catalysts in Russia and one rare earth metal (Honeycomb) catalyst in Korea). Catalytic activity was strongly influenced by the type and loading content of metal supported in catalyst. Catalytic performance showed the highest activity in Honeycomb catalyst including rare earth metal, which was the most expensive catalyst, while the next was the catalyst supported Cu with high content (AOK-78-52) and also that supported Cr and Co (AOK-78-56). However, both AOK-78-52 and AOK-78-56 catalysts that were very cheap had lower activation energy than Honeycomb catalyst. In the economical field, both AOK-78-52 and AOK-78-56 catalysts with transition metals showed a good alternative catalyst on the combustion of methane.

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
    • /
    • v.34 no.11
    • /
    • pp.2978-2983
    • /
    • 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%.

Characteristic Analysis of a SCR System using a Metal Foam in Diesel Engines (디젤 엔진에서 금속 폼을 적용한 SCR 촉매의 특성 분석)

  • Kim, Yongrae;Choi, Kyonam
    • Journal of ILASS-Korea
    • /
    • v.18 no.4
    • /
    • pp.196-201
    • /
    • 2013
  • SCR(Selective Catalytic Reduction) is a major after-treatment solution to reduce NOx emission in recent diesel engines. In this study, a metal foam is applied as an alternative SCR substrate and tested in a commercial diesel engine to compared with a conventional ceramic SCR system. Basic engine test from ND-13 mode shows that a metal foam catalyst has lower NOx conversion efficiency than a ceramic catalyst especially over $350^{\circ}C$. A metal foam catalyst has characteristics of high exhaust gas pressure before a SCR catalyst and high heat transfer rate due to its material and structure. NOx conversion efficiency of a metal foam catalyst shows an increasing tendency along with the increase of exhaust gas temperature by $500^{\circ}C$. The effect of urea injection quantity variation is also remarkable only at high exhaust gas temperature.

The Effect of Volume and Precious Metal loading on the Performance of Pd+Rh Three Way Catalysts (Pd+Rh 삼원촉매에서 촉매체적 및 귀금속량이 정화성능에 미치는 영향)

  • 김계윤
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.23 no.3
    • /
    • pp.389-397
    • /
    • 1999
  • Recently the use of Pd catalyst have been continued to expand because of cost avaliabilityand performance advantages. Especially the Pd+Rh catalyst instead of the Pt+Rh catalyst had been used for most of three way catalysts because of the more stringent emission standards and its higher temperature effectiveness. The main purpose of this study is to investigate the design parameter impacts on the Pd+Rh cat-alyst for the automotive exhaust catalysts application. This study was investigated on the catalyst efficiency for the volume and the precious metal loading of the Pd+Rh ceramic monolithic cata-lyst. And experiments concerning the effects of volume and precious metal loading on Pd+Rh three way catalysts were conducted to examined the catalyst light-off temperature and conver-sion efficiency on higher volume demonstrated almost similar performance. But their effects on higher precious metal loading demonstrated considerably better performance.

  • PDF

Durable Press Finishing Using Foam in Mixed Catalysts Textile Performance Properties in Metal Salt/oxycarboxylic Acid Mixed Catalysts (혼합촉매계에서의 거품을 이용한 듀어러블 프레스가공 금속염/옥시카르복시산 혼합촉매계에서의 가공효과-)

  • Lee, Jeong-Min;Bae, Gi-Seo;Kim, Byeong-Mi
    • Textile Science and Engineering
    • /
    • v.28 no.3
    • /
    • pp.67-76
    • /
    • 1991
  • A mixed catalyst system, metal salt/oxycarboxylic acid, using DMDHEU as a crosslinking reagent to improve the durable press (DP) properties of cotton fabrics was studied in relation to foam application. The easy-care properties and physical properties were measured and metal contents of DP finished fabrics were measured in order to study of catalysis mechanism of mixed catalyst system. Better results were obtained in the aluminum sulfate/oxycarboxylic acid mixed catalyst system compared with the magnesium chloride/oxycarboxylic acid mixed catalyst system and metal salt single catalyst system. The enhanced catalytic activity of a mixed catalyst system was attributed to the complex formation. The foam finishing treatment improved physical properties of fabrics compared with the fabrics treated by the conventional process.

  • PDF

A review of approaches for the design of high-performance metal/graphene electrocatalysts for fuel cell applications

  • Liu, Jiamin;Choi, Hyoung Jin;Meng, Long-Yue
    • Journal of Industrial and Engineering Chemistry
    • /
    • v.64
    • /
    • pp.1-15
    • /
    • 2018
  • Metal/graphene electrocatalysts have attracted growing attention in recent years due to their high catalyst loadings, good activity, and high stabilities. In this review, we summarize various approaches towards improving the efficiencies of metal/graphene electrocatalysts in terms of both cost and performance, based on optimization of the graphene support and the metal catalyst particles themselves. Thus, four different approaches are examined: (1) increasing the catalyst/support binding energy, (2) inducing additional anchoring and active sites, (3) enlarging the effective catalyst surface areas, and (4) enhancing the intrinsic catalytic activity through modification of the electronic structure. Finally, remarks on necessary future work in this area will be given in the context of producing metal/graphene electrocatalysts better suited to fuel cell applications.

Magnetic Separation of FCC Equilibrium Catalyst by HGMS

  • Xiang, Fazhu;He, Pingbo;Chen, Jin
    • Proceedings of the IEEK Conference
    • /
    • /
    • pp.770-775
    • /
    • 2001
  • Effects of magnetic field and carrier gas velocity on the magnetic separation of FCC catalyst by a high gradient magnetic separator were studied. The activities of the equilibrium catalyst, the magnetic particles and the nonmagnetic particles were evaluated in a fixed bed microreactor The results showed that heavy metal contaminated catalyst can be selectively separated by means of high gradient magnetic separation at magnetic field 0.5T and carrier gas velocity 0.3m.s$^{-1}$ , and lightly metal contaminated catalyst retained high catalytic activity.

  • PDF

A Study on the Thermal Aging and SOx Poisoning Characteristics on Alumina Supported Silver Catalyst under Diesel Engine Emission Condition (디젤엔진 배기가스조건하에서의 Pt 및 Ag 담지 알루미나 촉매의 열적 노화 특성과 SOx 피독 특성에 관한 연구)

  • 신병선
    • Journal of Korean Society for Atmospheric Environment
    • /
    • v.16 no.2
    • /
    • pp.199-208
    • /
    • 2000
  • In this study we investigated on the possibility of platinum and silver catalysts as de-NOx catalyst for activity test of supported metal oxide catalysts. the study was performed with the change of amount of metal and support types. The catalyst was prepared the activity of alumina supported silver catalyst produced by dry and wet impregnation method respectively and the resistance of sulfur for optimum supported silver catalyst,. As a result the activity of alumina supported platinum catalyst was showed at low temperature region but the case of silver catalyst activated at high temperature region. So we finally chose alumina supported silver catalyst as de-NOx target catalyst because alumina supported catalyst showed higher activity than alumina supported platinum catalyst.

  • PDF

The Performance of NI/$MgAl_2O_4$ Coated Metal Monolith in Natural Gas Steam Reforming for Hydrogen Production (NI/$MgAl_2O_4$코팅된 금속 모노리스 촉매의 수소 생산을 위한 천연가스 수증기 개질 반응특성에 관한 연구)

  • Choi, Eun-Jeong;Koo, Kee-Young;Jung, Un-Ho;Rhee, Young-Woo;Yoon, Wang-Lai
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.21 no.6
    • /
    • pp.500-506
    • /
    • 2010
  • The metal monolith catalyst coated with 15wt% Ni/$MgAl_2O_4$ is applied to the natural gas steam reforming for hydrogen production. To address the improvement of adherence between metal monolith and catalyst coating layer, the pre-calcination temperature as well as the coating conditions of $Al_2O_3$ sol are optimized. When the Fe-Cr alloy monolith is pre-calcined at $900^{\circ}C$ for 6 h, $Al_2O_3$ layer was formed uniformly on the entire surface of the metal substrate. It is seen that the formation of $Al_2O_3$ layer on the monolith surface is essential for the uniform coating of $Al_2O_3$ sol onto the monolith substrate. The monolith catalyst coated with 10wt% $Al_2O_3$ sol shows high $CH_4$ conversion and good thermal stability as compared with the monolith catalyst without $Al_2O_3$ sol coating under severe reaction conditions with high GHSV of 30,000 $h^{-1}$ at $700^{\circ}C$. In addition, the metal monolith catalyst shows higher catalytic activity and better thermal conductivity than 15wt% Ni/$MgAl_2O_4$ pellet catalyst.

A basic study on the recovery of Ni, Cu, Fe, Zn ions from wastewater with the spent catalyst (폐산화철촉매에 의한 폐수중 Ni, Cu, Fe, Zn이온 회수에 관한 기초연구)

  • Lee Hyo Sook;Oh Yeung Soon;Lee Woo Chul
    • Journal of the Korean Institute of Resources Recycling
    • /
    • v.13 no.2
    • /
    • pp.3-8
    • /
    • 2004
  • A basic study on the recovery of heavy metals such as Zn, Ni, Cu and Fe ions from wastewater was carried out with the spent iron oxide catalyst, which was used in the Styrene Monomer(SM) production company. The heavy metals could be recovered more than 98% with the spent iron oxide catalyst. The alkaline components of the spent catalyst could be precipitated the metal ions of the wastewater as metal hydroxides at the higher pH 10.6 in Ni, pH 8.0 in Cu, pH 6.5 in Fe, pH 8.5 in Zn. But the metal ions are adsorbed physically on the surface of the spent catalyst in the range of the pH of the metal hydroxides and pH 3.0, which is the isoelectric point of the iron oxide catalyst.