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        검색결과 5

        1.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Physical and electrochemical qualities were analyzed after KOH activation of a direct methanol fuel cell using needle coke as anode supporter. The results of research on support loaded with platinum-ruthenium suggest that an activated KOH needle coke container has the lowest onset potential and the highest degree of catalyst activity among all commercial catalysts. Through an analysis of the CO stripping voltammetry, we found that KOH activated catalysis showed a 21% higher electrochemical active surface area (ECSA), with a value of 31.37 m2/g, than the ECSA of deactivated catalyst (25.82 m2/g). The latter figure was 15% higher than the value of one specific commercial catalyst (TEC86E86).
        4,000원
        2.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Spinnable pitches and carbon fibers were successfully prepared from petroleum or coal pyrolysis residues. After pyrolysis fuel oil (PFO), slurry oil, and coal tar were simply filtered to eliminate the solid impurities, the characteristics of the raw materials were evaluated by elemental analysis, 13C nuclear magnetic resonance spectrometer, matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF-MS), and so on. Spinnable pitches were prepared for melt-spinning carbon fiber through a simple distillation under strong nitrogen flow, and further vacuum distillation to obtain a high softening point. Carbon fibers were produced from the above pitches by single-hole melt spinning and additional heat treatment, for oxidization and carbonization. Even though spinnable pitches and carbon fibers were processed under the same conditions, the melt-spinning and properties of the carbon fiber were different depending on the raw materials. A fine carbon fiber could not be prepared from slurry oil, and the different diameter carbon fibers were produced from the PFO and coal tar pitch. These results seem to be closely correlated with the initial characteristics of the raw materials, under this simple processing condition.
        4,000원
        3.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon nanofiber (CNF) grown catalytically was chemically activated with KOH to attain structural change of CNF. The structural changes of CNF through KOH activation were investigated by using BET and SEM. From the results of BET, it was found that KOH activation was effective to develop particular sizes of pores on the CNF surface, increasing the surface area of CNF. Activated CNF was applied as an anode catalyst support of fuel cell. The effects of different activation conditions including the activation temperature and the activation time on the specific surface area of the CNF activated with KOH were investigated to obtain appropriate structure as a catalyst support. The 60 wt% Pt-Ru catalyst prepared was observed by using TEM and XRD.
        4,000원
        4.
        2005.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bipolar plates require some specific properties such as electrical conductivity, mechanical strength, chemical stability, and low permeability for the fuel cell application. This study investigated the effects of carbon nanotube (CNT) contents and process conditions of hot press molding on the electrical and physical properties using CNT 3~7 wt% added graphite nano-composites in the curing temperatures range of 140~200℃ and pressure of 200~300 kg/cm2. Bulk density, hardness and flexural strength increased with increasing CNT contents, curing pressure and temperature. With the 7 wt% CNT added noncomposite, the electrical resistance improved by 30% and the flexural strength increased by 25% as compared to that without CNT at the temperature of 160℃ and pressure of 300 kg/cm2. These properties were close to the DOE reference criteria as bulk resistance of 13 mΩcm and tensile strength of 515 kg/cm2.
        4,000원
        5.
        2003.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Pt-Ru/Carbon as an anode catalyst supported on the commercial activated carbon (AC) having high surface area and micropore was characterized for application of Direct Methanol Fuel Cell (DMFC). The Pt-Ru/AC anode catalyst used in this experiment showed the performance of 600 mA/cm2 current density at 0.3 V. The borohydride reduction process using NaBH4, denoted as a process A, showed much higher current and power densities than process B prepared by changing the reduction and washing process of process A. The particle sizes are strongly affected by the reduction process than the specific surface area of raw active carbon and the sizes are almost constant when the specific surface area of carbon are over than the 1200 m2/g. Smaller particle size of catalyst and more narrow intercrystalite distance increased the performance of DMFC.
        4,000원