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Volumn 17, Issue 30, 2007, Pages 3197-3204

Independent verification of the saturation hydrogen uptake in MOF-177 and establishment of a benchmark for hydrogen adsorption in metal-organic frameworks

Author keywords

[No Author keywords available]

Indexed keywords

ADSORPTION ISOTHERMS; BENCHMARKING; ERROR ANALYSIS; MOLECULAR STRUCTURE; SAMPLING;

EID: 34547516632     PISSN: 09599428     EISSN: 13645501     Source Type: Journal    
DOI: 10.1039/b703608f     Document Type: Article
Times cited : (551)

References (47)
  • 23
    • 84942824971 scopus 로고    scopus 로고
    • Energy Efficiency and Renewable Energy Hydrogen, Fuel Cells and Infrastructure Technologies Program http://www1.eere.energy.gov/ hydrogenandfuelcells/
    • Energy Efficiency and Renewable Energy Hydrogen, Fuel Cells and Infrastructure Technologies Program http://www1.eere.energy.gov/ hydrogenandfuelcells/
  • 25
    • 84942823881 scopus 로고    scopus 로고
    • For instance, (1) non-ideality of H2 gas is emphasized under low temperature and high-pressure conditions, and (2) temperature gradient effect between a sample cell and a pressure transducer could bring a huge experimental error since the deviation increases with an increase in the inverse of measurement temperature. In other words, even if the experimental value at room temperature looks reasonable, there is no guarantee that the sorption system will also work properly at cryogenic conditions
    • For instance, (1) non-ideality of H2 gas is emphasized under low temperature and high-pressure conditions, and (2) temperature gradient effect between a sample cell and a pressure transducer could bring a huge experimental error since the deviation increases with an increase in the inverse of measurement temperature. In other words, even if the experimental value at room temperature looks reasonable, there is no guarantee that the sorption system will also work properly at cryogenic conditions
  • 31
    • 0004174919 scopus 로고
    • Ideal MOF-177 samples do not have any external surface but only an internal pore system, while actual crystalline samples (1) have finite size (i.e., sub-millimeter scale), (2) may be partly decomposed, (3) contain small amount of guest (mainly water) molecules. Therefore, it is difficult to conclude which value reflects an actual system. Considering that estimation of the true density of porous materials is not easy, 19 further consideration is beyond the scope of this article. However, we cannot fully exclude the possibility of helium adsorption on the MOF-177 surface. In case the slope of helium isotherm for the buoyancy correction can be underestimated, the Vp at UCLA may be overestimated
    • R. D. McCarty, J. Hord and H. M. Roder, Selected Properties of Hydrogen (Engineering Design Data), National Bureau of Standards, 1981, Monograph 168
    • (1981) Selected Properties of Hydrogen (Engineering Design Data), National Bureau of Standards
    • McCarty, R.D.1    Hord, J.2    Roder, H.M.3
  • 33
    • 84942817016 scopus 로고    scopus 로고
    • NIST chemistry webbook (thermophysical properties of fluid systems); http://webbook.nist.gov/chemistry/fluid/
    • NIST chemistry webbook (thermophysical properties of fluid systems); http://webbook.nist.gov/chemistry/fluid/
  • 40
    • 84942833949 scopus 로고    scopus 로고
    • Actual pore volume after H2 adsorption may be smaller than the accessible pore volume, Vpore. However, in the Gibbs definition of dividing surface, the adsorbed phase is a surface therefore it does not have a volume. Considering this, in terms of H2 storage, the important factor is not the thickness of the adsorbed layer but the number of H 2 molecules in the pores (which includes the bulk region), we believe that rough estimation of absolute adsorbed amounts is an important issue. However, this is beyond the scope of this paper
    • Actual pore volume after H2 adsorption may be smaller than the accessible pore volume, Vpore. However, in the Gibbs definition of dividing surface, the adsorbed phase is a surface therefore it does not have a volume. Considering this, in terms of H2 storage, the important factor is not the thickness of the adsorbed layer but the number of H 2 molecules in the pores (which includes the bulk region), we believe that rough estimation of absolute adsorbed amounts is an important issue. However, this is beyond the scope of this paper
  • 41
    • 84942821225 scopus 로고    scopus 로고
    • The BET method is still widely used for determining the surface area of micro-mesoporous materials. It is also recognized that the BET area should not be accepted as the true internal area of microporous solids having pores of molecular dimensions, such as in MOF materials. In this case, the value obtained should be regarded as an apparent or equivalent surface area
    • The BET method is still widely used for determining the surface area of micro-mesoporous materials. It is also recognized that the BET area should not be accepted as the true internal area of microporous solids having pores of molecular dimensions, such as in MOF materials. In this case, the value obtained should be regarded as an apparent or equivalent surface area
  • 44
    • 0001231062 scopus 로고
    • Strictly speaking, the heat of adsorption needs to be estimated based on the absolute adsorbed amount. 31 However, since the bulk density of H 2 under experimental conditions is small, we assumed Nex ≈ Nabs
    • J. Jagiello T. J. Bandosz K. Putyera J. A. Schwarz J. Chem. Eng. Data 1995 40 1288
    • (1995) J. Chem. Eng. Data , vol.40 , pp. 1288
    • Jagiello, J.1    Bandosz, T.J.2    Putyera, K.3    Schwarz, J.A.4
  • 47
    • 84942816111 scopus 로고    scopus 로고
    • note
    • This does not mean that volumetric measurements are better than gravimetric ones. Even in volumetric measurements either estimation of dead volume or unidealistic behavior of gas molecules under supercritical conditions can contain uncertainties


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.