• Title/Summary/Keyword: hydrogen adsorption

Search Result 434, Processing Time 0.034 seconds

Influence of Mg nanoparticles on Hydrogen Adsorption Behaviors of Multi-walled Carbon Nanotubes (다중벽 탄소나노튜브의 수소 흡착 거동에 대한 Mg 나노입자의 영향)

  • Yoo, Hye-Min;Park, Soo-Jin
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.05a
    • /
    • pp.160-160
    • /
    • 2011
  • In this work, magnesium (Mg) nanoparticles were plated onto the surfaces of multi-walled carbon nanotubes (MWNTs) in order to investigate the effects of their presence on the high pressure hydrogen storage behaviors of the resultant Mg/MWNTs. The structure of Mg/MWNTs was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The pore structure and total pore volumes of Mg/MWNTs were analyzed by $N_2$/77 K adsorption isotherms. The hydrogen storage behaviors of the Mg/MWNTs were investigated by BEL-HP at 298K and 100 bar. From the results, it was found that Mg particles were homogeneously distributed on the MWNT surfaces. The hydrogen storage capacity increased in proportion to the Mg content. It can be concluded that Mg paricles play an important role in hydrogen storage characteristics due to the hydrogen spillover effect.

  • PDF

Analysis of Adsorption Phenomena of Hydrogen on Carbon Nanotube usint Molecular Simulation (분자 모사를 이용한 탄소나노튜브의 수소 흡착 현상 분석)

  • Chun, Dong Hyuk;Moon, Jong-Ho;Kim, Hyun Uk;Park, Young Cheol;Lee, Tai-Yong
    • Journal of Energy Engineering
    • /
    • v.23 no.2
    • /
    • pp.7-12
    • /
    • 2014
  • Molecular simulation was performed to evaluate the possibility of hydrogen storage of carbon nanotubes. The equilibrium state of hydrogen adsorbed on carbon nanotubes was simulated by grand canonical Monte Carlo method at constant temperature and pressure. The interaction energy between hydrogen molecule and carbon nanotube was calculated by Lennard-Jones potential model. According to the interaction energy calculated, more hydrogen molecules were adsorbed on the inside than the outside of nanotubes. Whereas the adsorption strength was higher outside than inside. Adsorption capacity was investigated for various temperature and pressure. The maximum capacity of carbon nanotube for hydrogen storage was 2.5wt% at 200 K and 200 bar.

Studies on the Adsorbents for Cigarette Filter I. Effect of Pore Voume Distribution and Specific Area of Adsorbents on the Removal Efficiency of Smoke Components by Triple Filter (담배필터용 흡착제에 관한 연구 제1보. 흡착제의 종류와 동공특성이 담배연기성분 제거능에 미치는 영향)

  • 박태무;이영택;김성한;오영일
    • Journal of the Korean Society of Tobacco Science
    • /
    • v.10 no.1
    • /
    • pp.75-82
    • /
    • 1988
  • Cigarettes were made using a triple filter with several porous materials in its cavity. The removal effect of the adsorbents on carbon monoxide and hydrogen cyanide in cigarette smoke was investigated with the variation of their surface area and pore volume distributions. Several attempts were made to activated coconut shell based char under the fixed steam purging rate. 1. The specific surface area increased in number of micropore. It was found for transitional pore to have a little effect on the total surface area. 2. A Small amount of the particulate matter adsorbed on the adsorbents with transitional pores, Zeolite showed a little effect on the carbon monoxide adsorption though its small pore volume, but there was no significant difference in the adsorption capacity zeolite and the others. 3. In the adsorption for hydrogen cyanide as a vapor phase in cigarette smoke, the adsorption effect of the adsorbents increased remarkably with increasing their surface area and number of micropore. It was considered that the adsorbents with small pore volume like molecular seive 4A, in which the capillary diffusion of adsorbates could not be able, would not be effective for the adsorption of hydrogen cyanide.

  • PDF

Hydrogen adsorption properties of multi-walled carbon nanotubes (Multi-wall 탄소나노튜브의 수소 저장 특성)

  • Hwang, J.Y.;Lee, S.H.;Sim, K.S.;Kim, J.W.
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.12 no.1
    • /
    • pp.65-73
    • /
    • 2001
  • Carbon nanotubes were prepared by catalytic decomposition of $CH_4$ using Ni-MgO catalyst at various temperatures. $H_2$ effect on crystallinity and morphology during the synthesis of carbon nanotubes was investigated. The crystallinity and morphology were characterized by SEM, TEM, XRD, TGA, and Raman spectroscopy. In addition, the hydrogen adsorption properties were evaluated by PCT measurement in a hydrogen pressure range between 1 and 120 bar. The optimal synthesis temperature of carbon nanotubes was elevated in the presence of $H_2$, although significant difference of carbon nanotube morphology was not found. It is believed that hydrogen served as self-cleaner mops the amorphous carbon on the catalyst surface. It is proved that the carbon nanotubes have multi-walled structure, short length with a outer diameter of 20 ~40nm and open tips after elimination of the catalyst. The amount of hydrogen adsorbed in carbon nanotubes is increased as the pressure of hydrogen is increased and reaches 1.3 wt % under the hydrogen pressure of 120 bar at room temperature.

  • PDF

A Study on a Palladium-Silicon Garbide Schottky Diode as a Hydrogen Gas Sensor (Pd-SiC 쇼트키 다이오드의 수소 가스 감지 특성)

  • Lee, Joo-Hun;Lee, Young-Hwan;Kim, Chang-Kyo;Cho, Nam-Ihn
    • Proceedings of the KIEE Conference
    • /
    • 1998.11c
    • /
    • pp.858-860
    • /
    • 1998
  • A Pd-SiC Schottky diode for detection of hydrogen gas operating at high temperature was fabricated. Hydrogen-sensing behaviors of Pd-SiC Schottky diode have been analyzed as a function of hydrogen concentration and temperature by I-V and ${\Delta}I$-t methods under steady-state and transient conditions. The effect of hydrogen adsorption on the barrier height was investigated. Analysis of the steady-state kinetics using I-V method confirmed that the atomistic hydrogen adsorption process is responsible for the barrier height change in the diode.

  • PDF

Hydrogen Induced Reduction of Fe- and Co-Oxides with Addition of Ni and Pd (철과 코발트 산화물의 수소 환원에 니켈 및 팔라듐 첨가의 효과)

  • Kim, Jong-Pal
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.22 no.1
    • /
    • pp.35-41
    • /
    • 2011
  • Temperature programmed reduction experiments for Fe- and Co-oxides were performed and weight losses were carefully measured to calculate the extent of reduction. Addition of nickel and palladium affected the reduction by lowering the DTG peak temperature. Reduction experiments for the oxides on alumina were also studied and the effect of nickel and palladium addition was confirmed. And that was explained by means of increased adsorption of hydrogen and increased diffusion ability of the surface hydrogen.

Hydrogen Isotope Separation by using Zeolitic lmidazolate Frameworks (ZIF-11) (ZIF-11을 이용한 수소 동위원소 분리)

  • Lee, Seulji;Oh, Hyunchul
    • Korean Journal of Materials Research
    • /
    • v.30 no.12
    • /
    • pp.655-659
    • /
    • 2020
  • Hydrogen isotopes (i.e. deuterium and tritium) are supplied to the tokamak in the International Thermonuclear Experimental Reactor (ITER) fuel cycle. One important part of the ITER fuel cycle is the recycling of unused fuel back to the tokamak, as almost 99 % of fuel is unburned during fusion reaction. For this, cryogenic distillation has been used in the isotope separation system (ISS) of ITER, but this technique tends to be energy-intensive and to have low selectivity (typically below 1.5 at 24 K). Recently, efficient isotope separation by porous materials has been reported in the so-called quantum sieving process. Hence, in this study, hydrogen isotope adsorption behavior is studied using chemically stable ZIF-11. At low temperature (40 K ~ 70 K), the adsorption increases and the sorption hysteresis becomes stronger as the temperature increases to 70K. Molar ratio of deuterium to hydrogen based on the isotherms shows the highest (max. 14) ratio at 50 K, confirming the possibility of use as a potential isotope separation material.

UV-Cut Effects of Cotton Fabrics Treated with UV Absorbents (자외선 흡수제 처리에 의한 면직물의 자외선 차단 효과)

  • 지영숙;김상희
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.18 no.5
    • /
    • pp.622-627
    • /
    • 1994
  • The purpose of this study is to investigate the adsorption rate, adsorption quantities and the UV-Cut effects of cotton fabrics treated with several UV absorbents. The result of this study were as follows: cotton fabric treated with 2,2'-dihydroxy-4- methoxy-benzophenone shows more efficient than ones treated with 4-aminobenzoic acid and 2·hydroxy-1, 4-naphthoquinone in UV absorption. This may be due to the absorption of UV light by formation of intra moleculaar hydrogen bond. The formation of hydrogen bonds between hydrogen atoms of two hydroxy groups and one oxygen atom of carboxyl group in 2, 2'-dihydroxy-4-methoxy-benzophenone would be easier than that of the other absorbents. The adsorption isotherms of 4-aminobenzoic acid and 2-hydroxy-1, 4-naphthoquinone were similar to Freundlich type, while that of 2, 2'-Dihydroxy-4-methoxy-benzophenone was Henry type. Cotton fabrics treated with Antifade MC-100 and W Cut I-2 were just alike in UV absorption, but Antifade 8001 was inferior to the others.

  • PDF

Work Function Change of W(123) Plane Due to Hydrogen and Deuterium Adsorption at 78K (78K에서 수소 혹은 중수소 흡착으로 인한 W(123)면의 일함수 변화)

  • 박노길;김기석;김성수;정광호;황정남;최대선
    • Journal of the Korean Vacuum Society
    • /
    • v.1 no.1
    • /
    • pp.78-82
    • /
    • 1992
  • The changes in work function due to hydrogen and deuterium adsorption on W(123) plane are measured by means of Field Emission Method. In the case of hydrogen or deuterium adsorption, work function of W(123) plane at 78 K increase and after a maxium value, it decrease and saturated as increasing coverage. After annealing the tungsten emission tip at 200 K, the coverage corresponding to maximum change in work function was shifted toward low coverage and the effect of work function by terraces or steps of which orientation is [ O l l ] was observed.

  • PDF

A study on the Optimization of Hydrogen Production and Purification System for PEMFC (PEMFC에 사용되는 수소 생산 및 정화 기술 최적화 연구 )

  • SEOK KYUN KO;SANGYONG LEE
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.34 no.1
    • /
    • pp.1-7
    • /
    • 2023
  • A fuel handling process combined with a pressure swing adsorption system (PSA) was simulated to produce pure hydrogen with a purity greater than 99.97%. The simulation consists of two parts. The fuel processing part consisting of reformer and water-gas shift reaction was simulated with Aspen plus®, and the hydrogen purification part consisting of PSA was simulated with Aspen Adsorption®. In this study, the effect of reformer temperature and pressure on the total hydrogen production yield was investigated. Simulations were performed over a temperature range of 700 to 1,000℃ and a pressure range of 1 to 10 bar. The total hydrogen production yield increased with increasing temperature and decreasing pressure. The maximum hydrogen yield was less than 50% in the simulation and will be lower in the real process.