24 research outputs found

    The Physics of the B Factories

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    A DFT Study of Transition States for C-H Activation on the Ru(0001) Surface

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    The transition states of the elementary reactions for the dissociation of methane on the ruthenium (0001) surface have been investigated with DFT periodic calculations and the nudged elastic band method (NEB) for 25% coverages. The calculated barriers are 85 kJ mol(-1) for methane decomposition, 49 kJ mol(-1) for methyl decomposition, and 16 kJ mol(-1) for methylene decomposition, respectively. The decomposition of CHads requires the highest activation energy from the series with 108 kJ mol(-1). Discussion concerning chemical bonding aspects of the transition states structures is provided fo

    A theoretical study of CHx chemisorption on the Ru(0001) surface

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    The thermodynamics of methane decomposition on the ruthenium (0001) surface has been investigated with ab initio periodic calculations for coverages of 25% and 11%. All surface intermediates are more stable than the gas-phase methane even if the last step of the decomposition path (CH¿C+H) is highly endothermic. Amongst all of the surface species, CH appears to be the most stable, in agreement with experiments. All of the surface species (CHx=3,0 and H) adsorb on three-fold sites. Short-range lateral interactions between CHx=3,0 and H are also considered and are found to be mostly repulsive
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