TY - JOUR
T1 - Investigation on specific adsorption of hydrogen on lithium-doped mesoporous silica
AU - Kubo, Masaru
AU - Ushiyama, Hiroshi
AU - Shimojima, Atsushi
AU - Okubo, Tatsuya
N1 - Funding Information:
Acknowledgements This work was supported in part by the ENEOS Hydrogen Trust Fund and by a Grant-in-Aid for Scientific Research (B) from the Japan Society for the Promotion of Science (JSPS). M.K. acknowledges the support by a Grant-in-Aid for JSPS Fellows and Fellowship.
PY - 2011/2
Y1 - 2011/2
N2 - This paper reports the synthesis, structure, and hydrogen adsorption property of Li-doped mesoporous silica (MPS) with a 2D hexagonal structure. The Li-doping is achieved by impregnation of the cylindrical mesopores with an ethanol solution of lithium chloride followed by heat treatment. Detailed characterization by solid-state NMR, TG-MS, and FT-IR suggests that, during the heat treatment, lithium chloride reacts with surface ethoxy groups Si-OEt) to form =SiOLi groups, while ethyl chloride is released into the gas phase. The hydrogen uptake at 77 K and 1 atm increases from 0.68 wt% for the undoped MPS to 0.81 wt% for Li-doped MPS (Li-MPS). The isosteric heat of adsorption is 4.8 kJ∈mol-1, which is consistent with the quantum chemistry calculation result (5.12 kJ∈mol-1). The specific hydrogen adsorption on Li-MPS would be explained by the frontier orbital interaction between HOMO of hydrogen molecules and LUMO of = These findings provide an important insight into the development of hydrogen storage materials with specific adsorption sites.
AB - This paper reports the synthesis, structure, and hydrogen adsorption property of Li-doped mesoporous silica (MPS) with a 2D hexagonal structure. The Li-doping is achieved by impregnation of the cylindrical mesopores with an ethanol solution of lithium chloride followed by heat treatment. Detailed characterization by solid-state NMR, TG-MS, and FT-IR suggests that, during the heat treatment, lithium chloride reacts with surface ethoxy groups Si-OEt) to form =SiOLi groups, while ethyl chloride is released into the gas phase. The hydrogen uptake at 77 K and 1 atm increases from 0.68 wt% for the undoped MPS to 0.81 wt% for Li-doped MPS (Li-MPS). The isosteric heat of adsorption is 4.8 kJ∈mol-1, which is consistent with the quantum chemistry calculation result (5.12 kJ∈mol-1). The specific hydrogen adsorption on Li-MPS would be explained by the frontier orbital interaction between HOMO of hydrogen molecules and LUMO of = These findings provide an important insight into the development of hydrogen storage materials with specific adsorption sites.
KW - Hydrogen adsorption
KW - Li doping
KW - Mesoporous silica
KW - Quantum chemistry calculation
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U2 - 10.1007/s10450-010-9316-0
DO - 10.1007/s10450-010-9316-0
M3 - Article
AN - SCOPUS:79951551638
VL - 17
SP - 211
EP - 218
JO - Adsorption
JF - Adsorption
SN - 0929-5607
IS - 1
ER -