TY - GEN
T1 - Synthesis of microporous boron-substituted carbon (BCx) materials for hydrogen physisorption
AU - Chung, T. C.
AU - Jeong, Youmi
PY - 2009/12/1
Y1 - 2009/12/1
N2 - This paper discusses a new synthesis route to prepare boron substituted carbon (BCx) materials containing 3-15% B content and microporous microstructure. The BCx materials show a significantly higher hydrogen binding energy (10-20 kJ/mol)and physisorption capacity (2-3 times increase), compared with the corresponding carbonaceous (C) materials. Both enhancements are directly associated with B content and the acidity of B moiety. The chemistry involves a pyrolysis of the designed boron-containing polymeric precursors with the specific B contents. During pyrolysis, most of the boron moieties in the precursor were transformed into BCx material with the structure changing from puckered to graphitic controlled by pyrolysis temperature. On the other hand, the in situ formed by-products created a micro-porous structure. The micro-porous BCx material with B content >7% and surface area >700 m2/g has been prepared, which shows a reversible hydrogen physisorption capacity of 0.6 and 3.2 wt% at 293 and 77 K, respectively, under 40 bars hydrogen pressure. The physisorption results were further warranted by absorption isotherms and in situ 1H NMR studies, indicating a high binding energy of hydrogen molecules.
AB - This paper discusses a new synthesis route to prepare boron substituted carbon (BCx) materials containing 3-15% B content and microporous microstructure. The BCx materials show a significantly higher hydrogen binding energy (10-20 kJ/mol)and physisorption capacity (2-3 times increase), compared with the corresponding carbonaceous (C) materials. Both enhancements are directly associated with B content and the acidity of B moiety. The chemistry involves a pyrolysis of the designed boron-containing polymeric precursors with the specific B contents. During pyrolysis, most of the boron moieties in the precursor were transformed into BCx material with the structure changing from puckered to graphitic controlled by pyrolysis temperature. On the other hand, the in situ formed by-products created a micro-porous structure. The micro-porous BCx material with B content >7% and surface area >700 m2/g has been prepared, which shows a reversible hydrogen physisorption capacity of 0.6 and 3.2 wt% at 293 and 77 K, respectively, under 40 bars hydrogen pressure. The physisorption results were further warranted by absorption isotherms and in situ 1H NMR studies, indicating a high binding energy of hydrogen molecules.
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M3 - Conference contribution
AN - SCOPUS:78649800110
SN - 9780841200050
T3 - ACS National Meeting Book of Abstracts
BT - American Chemical Society - 238th National Meeting and Exposition, ACS 2009, Abstracts of Scientific Papers
T2 - 238th National Meeting and Exposition of the American Chemical Society, ACS 2009
Y2 - 16 August 2009 through 20 August 2009
ER -