TY - GEN
T1 - Thermodynamics of hydrogen release from the molecular BNC compounds
T2 - 232nd American Chemical Society Meeting and Exposition
AU - Gutowski, Maciej
AU - Li, Jun
AU - Schenter, Gregory K.
AU - Autrey, Tom
AU - Linehan, John
PY - 2006/12/1
Y1 - 2006/12/1
N2 - Boron-nitrogen hydride (BNHx) materials display favorable gravimetric and volumetric densities of hydrogen. The hydrogen release is, however, too exothermic for direct practical applications and/or on-board regeneration. Different approaches aiming at improved thermodynamics are being pursued. In the past we suggested that the (BNHx) compounds infused in nanoporous silica undergo dehydrogenation reactions with more favourable thermodynamics than the neat (BNHx) compounds. Here we present results for molecular systems, in which the (BNHx) compounds are chemically modified. We recognize that the dehydrogenation of cylohexane is endothermic while the dehydrogenation of perhydroborazine, which is a BN analog of cyclohexane, is exothermic. Next, we recognize that the BN unit is isoelectronic with the CC unit. Finally we propose that ByNyCz compounds might display thermodynamics for dehydrogenation intermediate between this for carbon based and that for BN based hydrides. The thermodynamics of dehydrogenation calculated for molecular, cyclic carbon-, BN-, and BNC- based hydrides confirms this hypothesis. The calculations were performed at the density functional level of theory with a hybrid B3LYP exchange-correlation functional.
AB - Boron-nitrogen hydride (BNHx) materials display favorable gravimetric and volumetric densities of hydrogen. The hydrogen release is, however, too exothermic for direct practical applications and/or on-board regeneration. Different approaches aiming at improved thermodynamics are being pursued. In the past we suggested that the (BNHx) compounds infused in nanoporous silica undergo dehydrogenation reactions with more favourable thermodynamics than the neat (BNHx) compounds. Here we present results for molecular systems, in which the (BNHx) compounds are chemically modified. We recognize that the dehydrogenation of cylohexane is endothermic while the dehydrogenation of perhydroborazine, which is a BN analog of cyclohexane, is exothermic. Next, we recognize that the BN unit is isoelectronic with the CC unit. Finally we propose that ByNyCz compounds might display thermodynamics for dehydrogenation intermediate between this for carbon based and that for BN based hydrides. The thermodynamics of dehydrogenation calculated for molecular, cyclic carbon-, BN-, and BNC- based hydrides confirms this hypothesis. The calculations were performed at the density functional level of theory with a hybrid B3LYP exchange-correlation functional.
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M3 - Conference contribution
AN - SCOPUS:34047256105
SN - 0841274266
SN - 9780841274266
T3 - ACS National Meeting Book of Abstracts
BT - Abstracts of Papers - 232nd American Chemical Society Meeting and Exposition
Y2 - 10 September 2006 through 14 September 2006
ER -