Development of Nanoporous Electodes Architecture for Polymer Electrolyte Membrane Fuel Cells using Structure-Directing Agents

DoctorPolymer electrolyte membrane fuel cells (PEMFCs), which directly convert the chemical energy of fuels to electrical energy, have attracted much attention for various applications in transportation as well as stationary and portable power generation due to their high efficiencies and low emissions. Though various technical breakthroughs have been achieved in the past, many challenges such as cost reduction and performance improvement, and durability enhancement must be overcome before commercialization of PEMFCs is possible. Therefore, one of the main objectives in PEMFC technology is the development of high-performing electrocatalyst support materials by a low-cost route. Various forms of ordered mesoporous carbons (OMCs) are good candidates for support materials due to their high electrical conductivity, large surface area, interconnected porous structure, chemical stability, and their wide availability. In this study, we introduce a ‘one-pot’ synthetic strategy using the unique properties of amphiphilic block copolymers as structure directing agents to synthesize mesoporous carbon-based nanocomposites with functionalities such as nanoparticle incorporation and controlled composition and pore size. We prepared ordered 2-D hexagonal, large-pore mesoporous carbon/silica composites with highly dispersed intermetallic PtPb nanocatalysts for use as anode catalysts in direct formic acid fuel cells. Uniform and large pores, dispersed with small intermetallic PtPb nanocrystals, enable pore backfilling with ionomers and formation of the desired triple-phase boundary in single cells. The materials show more than 10 times higher mass activities and significantly lower onset potentials for formic acid oxidation as compared with commercial Pt/C, as well as high stability due to better resistance toward CO poisoning. In single cells, the maximum power density was higher than that of commercial Pt/C, and the stability was highly improved compared with commercial Pd/C. Although the resulting materials showed high activity and stability for formic acid oxidation, the size of the intermetallic nanoparticles was much larger (ca. 12 nm) than that of commercial Pt/C (2 nm) and Pd/C (7 nm). Because the electrocatalytic activity is increases linearly with a decrease in particle size, we also investigated a modified “one-pot” method that enables small-sized nanoparticles to be encapsulated within OMC-based nanocomposites without nanoparticle aggregation or coalescence. During the synthetic process, metal-support interactions, dependent on the differing chemical properties of support materials, can affect the size and distribution of metal nanoparticles in the final materials. The resulting aggregation-free, small-sized intermetallic PtPb and Pt3Co nanocomposites were successfully employed as anodes for formic acid (FA) oxidation and as cathodes for the oxidation reduction reaction (ORR), respectively, and showed superior catalytic performance over commercial Pt/C

One-Pot Synthesis of Intermetallic PtPb Nanocatalysts in Ordered, Large-Pore Mesoporous Carbon/Silica for Direct Formic Acid Fuel Cell Anodes

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One-pot Multi Catalyst System using Fe3O4 Magnetic Nanoparticles and Oxidases as a Colorimetric Sensor

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Functional Ordered Mesoporous Metal Oxides and Carbons for Fuel Cell Catalysts

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Block Copolymer Directed Synthesis of high performance PtPb nanocatalysts in ordered mesoporous carbon/silica toward direct formic acid fuel cell anodes

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Fabrication of Nanostructured Multi-catalyst System Entrapping Fe3O4 Magnetic Nanoparticles and Oxidase in Large Pore Sized Mesoporous Materials for Colorimetric Biosensing and Electrochemical Biosensing

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Mesoporous Silica Conjugate Integrating Magnetic Nano Particles Having Peroxidase Activity and Enzymes and Method for Manufacturing the Same

본 발명은 과산화효소(peroxidase) 활성을 가지는 자성 나노입자와 효소가 다공성 실리카의 기공 내에 고정되어 있는 다공성 실리카 복합체 및 그 제조방법에 관한 것으로, 보다 상세하세는, 표면적 및 기공 부피가 큰 다공성 실리카의 기공 안에 과산화효소로서의 활성을 띄는 자성 나노 입자와 효소가 동시에 집적되어 있는 다공성 실리카 복합체 및 그 제조방법에 관한 것이다. 본 발명에 따른 다공성 실리카 복합체는 다양한 질병의 마커가 되는 포도당, 갈락토스, 콜레스테롤 등의 소분자 물질, 단백질, DNA, 병원균 등을 민감하게 진단할 수 있고, 자성 나노 입자 및 효소를 다공성 실리카에 집적함으로써 단위 개체당 활성이 높아 고감도 정량 분석이 가능하며, 자성 나노입자를 이용하여 효율적인 분리와 재사용이 가능한 효과를 가진다

Block Copolymer Directed ‘One-Pot’ Simple Synthesis of L10 Phase FePt Nanoparticles inside Cellular Ordered Mesopores

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