• Title, Summary, Keyword: Hydrogen Storage capacity

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Effect of Nickel Oxide on Hydrogen Storage Behaviors of Mesoporous SBA-15

  • Lee, Seul-Yi;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • pp.231-231
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    • 2009
  • In this work, we prepared the Ni-loaded porous SBA-15 (SBA-15) by a depositionprecipitation (D-P) method, in order to enhance the hydrogen storage capacity. The structure and morphology of the Ni/SBA-15 were characterized by X-ray diffraction (XRD) and field emission transmission electron microscopy (FE-TEM). The results showed that, at the Ni loading used at the DP times in the range of 0-120 min, SBA-15 preserved the well-ordered hexagonal porous arrangement. The textural properties of the Ni/SBA-15 were analyzed using N2 adsorption isotherms at 77 K. Specific surface area and mesopore volume of the samples were determined from the Brunauer-Emmett-Teller (BET) equation and Barrett-Joiner-Halenda (BJH) method, respectively. The hydrogen storage capacity of the Ni/SBA-15 was evaluated at 298 K/10 MPa. The hydrogen storage capacity of the Ni/SBA-15 was increased in accordance with Ni content. Consequently, it was found that the presence of Ni on mesoporous SBA-15 created hydrogen-favorable sites which enhanced the hydrogen storage capacity by spillover effect.

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Hydrogen Storage Behaviors of Multi-walled Carbon Nanotubes Modified by Physical Activation Process (기상활성화 표면처리된 다중벽 탄소나노튜브의 수소저장거동)

  • Park, Soo-Jin;Lee, Seul-Yi;Kim, Byung-Joo
    • 한국신재생에너지학회:학술대회논문집
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    • pp.765-768
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    • 2009
  • In this work, we prepared the activated multi-walled carbon nanotubes (Acti-MWNTs) with well developed physical surface structures, high specific surface area, and higher adsorption capacity by a physical activation process, in order to enhance the hydrogen storage capacity. The Acti-MWNTs' changes in the crystalline phase and in their lattice distortions were characterized by X-ray diffraction (XRD). The textural properties of the Acti-MWNTs were investigated by a nitrogen adsorption isotherms by Brunauer-Emmett-Teller (BET) equation and Harvath-Kawazoe (H-K) calculation, respectively. The hydrogen storage capacity of the Acti-MWNTs was investigated by BEL-HP at 298 K/100 bar. The hydrogen storage capacity of the Acti-MWNTs was improved with the physical activation, resulted from the formation of new hydrogen-favorable sites on the Acti-MWNT surfaces. In conclusion, the physical activation was one of the effective method to enhance the hydrogen storage capacity of the MWNTs.

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Review : Hydrogen Storage in Solid State (고체상 수소저장기술 동향)

  • Lee, Jun-Wung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.6
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    • pp.1153-1171
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    • 2010
  • Hydrogen is the most abundant element in the universe. Although hydrogen can produce three times more energy than gasoline and seven times than coal, the most challenging problem in utilizing hydrogen as energy carrier is its storage problem. In contrast to the liquid hydrocarbon, hydrogen can not be stored or transported easily and safely because of its extremely low boiling point(21K). Recently scientists have made a tremendous achievement in storing hydrogen capacity in solid state materials such as carbon based and metal organic frameworks materials as well as metal hydrides. In this review the author reviewed the status of the hydrogen storage technologies in solid state, the advantages and disadvantages in each category of materials and the future prospects of hydrogen storage.

Effect of surface treatments on Single-walled Carbon nanotubes(SWNTs) for Hydrogen storage (수소저장용 단일벽 탄소나노튜브의 표면처리 효과)

  • Lee, Young-Seak;Cho, Se-Ho;Park, Il-Nam
    • Transactions of the Korean hydrogen and new energy society
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    • v.16 no.4
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    • pp.343-349
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    • 2005
  • In this study, We had surface-treated single-walled carbon nanotubes (SWNTs) for improving hydrogen storage capacity. The SWNTs were treated by heat treatment, acid treatment and fluorinated at various temperatures. The SWNTs were characterized by Raman spectroscopy and TEM and estimated hydrogen storage capacities at 303K. As shown Raman spectra and TEM images, the structure of fluorinated SWNTs were stable at 423K but changed to the MWNTs-like structure or onion structure over 523K. Hydrogen storage capacity of SWNTs fluorinated at 423K was remarkably increased 2.6 times than that of pristine SWNTs. For SWNTs fluorinated at 573K, the amount of hydrogen adsorbed wasn't increased compared with SWNTs fluorinated at 423K. Therefore, high hydrogen storage capacity of SWNTs could be archived by fluorinated condition at 423K, which was not changed SWNT structure.

A Study on Performance Characteristics of Ti-Zr Type Metal Hydrides and Hydrogen Storage Cylinders with the Hydrides (Ti-Zr계 금속수소화물 및 수소저장실린더의 성능특성 연구)

  • Kim, Ki-Youl
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.4
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    • pp.519-526
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    • 2012
  • Recently fuel cell is considered to be a new technology that can substitute the ICE(Internal Combustion Engine) as well as overcome environmental issues. In military applications, fuel cell has an unique advantages, which are quietness, namely, stealth. The environmental requirement such as shock and vibration in military application, however, is very severe comparing to civilian demand. Especially, the safety concerning hydrogen storage is the most important problem. Among the candidate methods to store hydrogen, the metal hydride storage is promising method owing to the storage mechanism of chemical absorption of hydrogen to metal hydrides. In this study, the new composition of Ti-Zr type metal hydride(A composition) was suggested and investigated to increase the hydrogen storage capacity. For comparison, the hydrogen charge-discharge properties were investigated with the commercialized Ti-Zr type metal hydride(B composition) using PCT(Pressure-Composition-Temperature) measurement. Also two hydrogen storage cylinders were loaded with each metal hydride and their hydrogen charging and discharging characteristics were investigated. As a result, it was found that the new Ti-Zr type metal hydride has a slightly higher hydrogen storage capacity compared to commercial Ti-Zr type metal hydride.

Study on the Application for Hydrogen Storage Tank of MmNi4.5Mn0.5Zrx(x=0, 0.025, 0.05, 0.1) Alloys Containing Excess Zr (과잉 Zr을 첨가한 MmNi4.5Mn0.5Zrx(x=0, 0.025, 0.05, 0.1) 합금의 수소용기 적용에 관한 연구)

  • Kang, Kil-Ku;Park, Sung-Gap;Kang, Sei-Sun;Kwon, Ho-Young
    • Korean Journal of Materials Research
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    • v.12 no.8
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    • pp.624-633
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    • 2002
  • In order to improve the hydrogen storage capacity and the activation properties of the hydrogen storage alloys, the rare-earth metal alloy series, MmN $i_{4.5}$M $n_{0.5}$Z $r_{x}$(x=0, 0.025, 0.05, 0.1), are prepared by adding excess Zr in MmN $i_{4.5}$M $n_{0.5}$ alloy. The various parts in hydrogen storage vessel consisted of copper pipes reached the setting temperature within 4~5 minutes after heat addition, which indicated that storage vessel had a good heat conductivity required in application. The performance test on storage vessel filled with rare-earth metal alloys of 1000 gr was also conducted after hydrogen charging for 10 min at $18^{\circ}C$ under 10 atm. It showed that the average capacity of discharged hydrogen volume was found to be for $MmNi_{4.5}$ $Mn_{0.5}$ and $MmNi_{4.5}$ $Mn_{x}$ 0.5/$Zr_{samples}$ indicated that the released amount of hydrogen for this $AB_{5}$ type alloys was more than 92 % of theoretic value, and also it was found that the optimum discharging temperature for obtaining an appropriate pressure of 3 atm was determined to be $V^{\circ}C$ for $MmNi_{4.5}$ $Mn_{0.5}$$Zr_{x}$(x=0, 0.025, 0.05, 0.1) hydrogen storage alloys. The released amount of these hydrogen storage samples was 125 $\ell$ , 122.4 $\ell$ and 108.15 $\ell$/kg for $MmNi_{4.5}$ $Mn_{0.5}$ $Zr_{0.025}$ $MmNi_{4.5}$M $n_{0.5}$Z $r_{0.05}$, and MmN $i_{4.5}$ Mn_0.5$Zr_{0}$, at $70^{\circ}C$ respectively. Amount of the 2nd phases increase with increase on Zr contents in $MmNi_{4.5}$$Mn_{0.5}$ $Zr_{ 0.1}$/ alloy. This phenomenon indicates that$ ZrNi_3$ in $MmNi_{4.5}$ $Mn_{0.5}$ $Zr_{x}$ / phase, which shows the maximum storage capacity and the strong resistance to intrinsic degradation, is considered as a proper alloy for hydrogen storage. As the Zr contents increase, the activation time and the plateau pressure decreases and sloping of the plateau pressure increases.creases.eases.s.

Hydrogen Storage Using Pd Doped Mesoporous Carbon Materials (팔라듐이 담지된 중형 기공성 탄소 재료를 이용한 수소 저장)

  • Kim, Wooyoung;Kim, Dongmin;Hong, Youngteak;Kang, Taegyun;Yi, Jongheop
    • Clean Technology
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    • v.12 no.2
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    • pp.107-111
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    • 2006
  • Two types of mesoporous carbons, CMK-3 and CMK-5, were prepared using mesoporous silica as a removable template, and their hydrogen storage capacities were evaluated. For the purpose of comparison, MWCNT (multi-walled carbon nanotubes) was selected and the adsorption of hydrogen was measured. The amount of hydrogen adsorbed on carbon materials was found to be closely related to the surface areas of carbon samples: The higher the surface area of the carbon material, the larger amount of hydrogen was adsorbed. The hydrogen storage capacity increased in the order of CMK-5 > CMK-3 > MWCNT. In addition, hydrogen storage capacity was greatly enhanced by the Pd-doping onto CMK-5. When the metallic Pd was doped on the carbon material, the adsorption amount of hydrogen via a hydrogen spill-over mechanism was crucial to the hydrogen storage capacity of Pd-doped CMK-5.

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Structural transition of Ti-Cr-V alloys with hydrogenation and dehydrogenation and the improvement of their hydrogen storage properties by heat treatment (Ti-Cr-V 합금의 수소화-탈수소화에 따른 상천이 및 열처리에 의한 수소저장특성의 향상)

  • You, Jeong-Hyun;Cho, Sung-Wook;Shim, Gun-Choo;Choi, Good-Sun;Park, Choong-Nyeon;Choi, Jeon
    • Transactions of the Korean hydrogen and new energy society
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    • v.17 no.2
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    • pp.125-132
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    • 2006
  • The alloys which compositions were represented by the formula, $Ti_{(0.22+X)}Cr_{(0.28+1.5X)}V_{(0.5-2.5X)}$ ($0{\leq}X{\leq}0.12$), had the total hydrogen storage capacity higher than 3 wt% and the effective hydrogen storage capacity higher than 1.4 wt%. Particularly, among all the tested alloys, the $Ti_{0.32}Cr_{0.43}V_{0.25}$ alloy exhibited the best effective hydrogen storage capacity of 1.65 wt%. Furthermore, the reversible bcc${\leftrightarrow}$fcc structural transition was observed with hydrogenation and dehydrogenation, which predicted the possibility of pressure cycling. EDS analysis revealed micro-segregation, which suggested the necessity of microstructure homogenization by heat treatment. The $Ti_{0.32}Cr_{0.43}V_{0.25}$ alloy was selected for heat treatment and for other related studies. The results showed that the total and the effective hydrogen storage capacity increased to 3.7 wt% and 2.3 wt%, respectively. The flatness of the plateau region was also greatly improved and heat of hydride formation was determined to be approximately -36 kJ/mol $H_2$.

Ni Nanoparticles-hollow Carbon Spheres Hybrids for Their Enhanced Room Temperature Hydrogen Storage Performance

  • Kim, Jin-Ho;Han, Kyu-Sung
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.6
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    • pp.550-557
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    • 2013
  • A glucose hydrothermal method is described for preparing hollow carbon spheres (HCS), which have a regular morphology and a high Brunauer-Emmett-Teller surface area of 28.6 m2/g. Scanning electron microscopy shows that they have thin shells and diameter between 2 and 8 ${\mu}m$. The HCSs were modified for the enhanced room temperature hydrogen storage by employing Ni nanoparticles on their surface. The Ni-decorated HCSs were characterized by X-ray diffraction, transmission electron microscopy coupled with an energy dispersive spectroscope, and an inductively coupled plasma spectrometer, indicating that fine and well-distributed Ni nanoparticles can be accomplished on the HCSs. The hydrogen uptake capacity in HCSs with and without Ni loading was evaluated using a high-pressure microbalance at room temperature under a hydrogen pressure upto 9 MPa. As much as 1.23wt.% of hydrogen can be stored when uniformly distributed Ni nanoparticles are formed on the HCSs, while the hydrogen uptake capacity of as-received HCSs was 0.41 wt.%. For Ni nanoparticle-loaded HCSs, hydrogen molecules could be easily dissociated into atomic hydrogen and then chemically adsorbed by the sorbents, leading to an enhanced capacity for storing hydrogen.

Preparation and Characterization of Ultramicroporous Carbons for Hydrogen Storage (초미세기공을 지니는 탄소분자체의 수소저장거동)

  • Lee, Seul-Yi;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
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    • pp.158.1-158.1
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    • 2011
  • In this work, we prepared ultramicroporous carbons (UC) prepared by pyrolyzing poly(vinylidene fluoride) with different carbonization temperatures, and investigated the hydrogen storage behaviors. The surface functional groups and specific elements of UC were confirmed by Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), respectively. Textural properties were analyzed using $N_2$ adsorption isotherms at 77 K. The hydrogen storage capacity of the UC samples were investigated by BEL-HP at 298 K/10 MPa. From the results, it was found that the hydrogen storage capacity was enhanced with increasing of specific surface area, resulting from the formation of ultramicropore on the UC.

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