2008-07-17
org.kosen.entty.User@7d1d6898
이형진(hjleev)
- 1
meso porous metal 나노 platinum입자가 battery에 어떻게 응용이 될 수가 있나요?
사이언스에 나왔던데...궁금해서요..
고견들 부탁드립니다..
Mesoporous Metals
Self-assembly steers platinum nanoparticles to form large-pore metallic structures
Mitch Jacoby
CORNELL UNIVERSITY researchers have developed a synthesis for well-ordered metallic materials that feature pores in the previously unattainable tens-of-nanometers size range (Science 2008, 320, 1748). Known as “mesoporous“ metals, these kinds of materials can mediate a substantial flow of molecules through their large pores and may be useful as fuel-cell electrodes or in other applications such as catalysis and photonics.
Scott C. Warren & Ulrich Wiesner/Cornell
A new synthesis guides platinum nanoparticles to form ordered materials with 10–20-nm-sized pores.
The variety and number of porous materials, including zeolite-type compounds and metal-organic frameworks, have grown substantially in recent years due to advances in synthesis methods. Yet those procedures, which often involve organic compounds as structure-directing agents, have not made it easy to prepare ordered metals with pores larger than roughly 2 nm.
“The challenge with metals is that their high surface energies cause the particles to cluster,“ explains Ulrich Wiesner, the Cornell material scientist who led the team. This tendency to aggregate makes it difficult to coax metal particles into lining up in an orderly fashion, which is a critical step in forming ordered materials.
Rather than following what Wiesner calls “the traditional 'heat it and beat it' approach“ to structuring metals, Wiesner, Scott C. Warren, and their coworkers prepared their materials through self-assembly of block copolymers and stabilized platinum nanoparticles.
Specifically, the team used ionic-liquid ligands (methylammonium chloride compounds) to render the 1.8-nm platinum particles soluble and to prevent their agglomeration. When combined with isoprene-methacrylate block copolymers, the metal particles self-assemble to form ordered metal-organic hybrid structures. Finally, by applying various heat treatments and etching procedures, the researchers removed the organic components, leaving a metallic platinum material with an orderly array of pores measuring 10–20 nm.
Describing the work as “a significant advance,“ Edward J. Kramer, a professor of materials and chemical engineering at the University of California, Santa Barbara, remarks that the novel material may lead to a host of applications. He notes, for example, that in addition to potential use in battery and fuel-cell electrodes, the new material may also be useful for chemical separations and fabrication of mesoporous crystals for catalysis
- mesoporous
- battery
- nanoplatinum
지식의 출발은 질문, 모든 지식의 완성은 답변!
각 분야 한인연구자와 현업 전문가분들의 답변을 기다립니다.
각 분야 한인연구자와 현업 전문가분들의 답변을 기다립니다.
답변 1
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답변
김도형님의 답변
2008-07-18- 0
연료 전지에서 백금은 전극으로 사용되며 산화(음극; 수소) 또는 환원(양극; 산소)시키는 촉매 역할을 하게 됩니다. 백금은 효율적이기는 하나 고가의 귀금속이기 때문에 촉매전극을 백금 대신 효율면에서 큰 손해를 보지 않는 다른 금속으로 바꾸는 연구가 많이 이루어지고 있습니다. 같은 의미로 백금 전극을 써서 현재의 효율보다 월등히 높은 효율을 달성할 수 있다면 “고가“라는 단점을 극복할 수 있게 됩니다. Nanoporous 백금의 경우 일반적인 표면을 가지는 백금에 비하여 촉매 반응이 일어나는 유효 표면적이 대단히 넓기 때문에 동일한 크기의 전극이라면 효율이 월등히 높아집니다. 기사에서는 이런 응용 가능성을 언급한 것으로 생각됩니다. >meso porous metal 나노 platinum입자가 battery에 어떻게 응용이 될 수가 있나요? >사이언스에 나왔던데...궁금해서요.. >고견들 부탁드립니다.. >Mesoporous Metals >Self-assembly steers platinum nanoparticles to form large-pore metallic structures >Mitch Jacoby >CORNELL UNIVERSITY researchers have developed a synthesis for well-ordered metallic materials that feature pores in the previously unattainable tens-of-nanometers size range (Science 2008, 320, 1748). Known as “mesoporous“ metals, these kinds of materials can mediate a substantial flow of molecules through their large pores and may be useful as fuel-cell electrodes or in other applications such as catalysis and photonics. > >Scott C. Warren & Ulrich Wiesner/Cornell >A new synthesis guides platinum nanoparticles to form ordered materials with 10–20-nm-sized pores. >The variety and number of porous materials, including zeolite-type compounds and metal-organic frameworks, have grown substantially in recent years due to advances in synthesis methods. Yet those procedures, which often involve organic compounds as structure-directing agents, have not made it easy to prepare ordered metals with pores larger than roughly 2 nm. > >“The challenge with metals is that their high surface energies cause the particles to cluster,“ explains Ulrich Wiesner, the Cornell material scientist who led the team. This tendency to aggregate makes it difficult to coax metal particles into lining up in an orderly fashion, which is a critical step in forming ordered materials. > >Rathe>r than following what Wiesner calls “the traditional 'heat it and beat it' approach“ to structuring metals, Wiesner, Scott C. Warren, and their coworkers prepared their materials through self-assembly of block copolymers and stabilized platinum nanoparticles. > >Specifically, the team used ionic-liquid ligands (methylammonium chloride compounds) to render the 1.8-nm platinum particles soluble and to prevent their agglomeration. When combined with isoprene-methacrylate block copolymers, the metal particles self-assemble to form ordered metal-organic hybrid structures. Finally, by applying various heat treatments and etching procedures, the researchers removed the organic components, leaving a metallic platinum material with an orderly array of pores measuring 10–20 nm. > >Describing the work as “a significant advance,“ Edward J. Kramer, a professor of materials and chemical engineering at the University of California, Santa Barbara, remarks that the novel material may lead to a host of applications. He notes, for example, that in addition to potential use in battery and fuel-cell electrodes, the new material may also be useful for chemical separations and fabrication of mesoporous crystals for catalysis >