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S Wang,
V Petzold,
V Tripkovic,
J Kleis,
J G Howalt,
E Skúlason,
E M Fernández,
B Hvolbæk,
G Jones, A Toftelund,
H Falsig,
M Björketun,
F Studt,
F Abild-Pedersen,
J Rossmeisl,
J K Nørskov,
T Bligaard
[show abstract]
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ABSTRACT: We analyse the transition state energies for 249 hydrogenation/dehydrogenation reactions of atoms and simple molecules over close-packed and stepped surfaces and nanoparticles of transition metals using Density Functional Theory. Linear energy scaling relations are observed for the transition state structures leading to transition state scaling relations for all the investigated reactions. With a suitable choice of reference systems the transition state scaling relations form a universality class that can be approximated with one single linear relation describing the entire range of reactions over all types of surfaces and nanoclusters.
Physical Chemistry Chemical Physics 12/2011; 13(46):20760-5. · 3.57 Impact Factor
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A Vojvodic,
F Calle-Vallejo,
W Guo,
S Wang, A Toftelund,
F Studt,
J I Martínez,
J Shen,
I C Man,
J Rossmeisl,
T Bligaard,
J K Noørskov,
F Abild-Pedersen
[show abstract]
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ABSTRACT: Versatile Brønsted-Evans-Polanyi (BEP) relations are found from density functional theory for a wide range of transition metal oxides including rutiles and perovskites. For oxides, the relation depends on the type of oxide, the active site, and the dissociating molecule. The slope of the BEP relation is strongly coupled to the adsorbate geometry in the transition state. If it is final state-like the dissociative chemisorption energy can be considered as a descriptor for the dissociation. If it is initial state-like, on the other hand, the dissociative chemisorption energy is not suitable as descriptor for the dissociation. Dissociation of molecules with strong intramolecular bonds belong to the former and molecules with weak intramolecular bonds to the latter group. We show, for the prototype system La-perovskites, that there is a "cyclic" behavior in the transition state characteristics upon change of the active transition metal of the oxide.
The Journal of chemical physics 06/2011; 134(24):244509. · 3.09 Impact Factor
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A. Vojvodic,
F. Calle-Vallejo,
W. Guo,
S. Wang, A. Toftelund,
F. Studt,
J. I. Martínez,
J. Shen,
I. C. Man,
J. Rossmeisl,
T. Bligaard,
J. K. Norskov,
F. Abild-Pedersen
241st National Meeting and Exposition of the American-Chemical-Society (ACS), Anaheim, CA; 03/2011
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J S Hummelshøj,
D D Landis,
J Voss,
T Jiang,
A Tekin,
N Bork,
M Dułak,
J J Mortensen,
L Adamska,
J Andersin, [......],
V Viswanathan,
A Vojvodic,
S Wang,
J Wellendorff,
K S Thygesen,
J Rossmeisl,
T Bligaard,
K W Jacobsen,
J K Nørskov,
T Vegge
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ABSTRACT: We present a computational screening study of ternary metal borohydrides for reversible hydrogen storage based on density functional theory. We investigate the stability and decomposition of alloys containing 1 alkali metal atom, Li, Na, or K (M(1)); and 1 alkali, alkaline earth or 3d/4d transition metal atom (M(2)) plus two to five (BH(4))(-) groups, i.e., M(1)M(2)(BH(4))(2-5), using a number of model structures with trigonal, tetrahedral, octahedral, and free coordination of the metal borohydride complexes. Of the over 700 investigated structures, about 20 were predicted to form potentially stable alloys with promising decomposition energies. The M(1)(Al/Mn/Fe)(BH(4))(4), (Li/Na)Zn(BH(4))(3), and (Na/K)(Ni/Co)(BH(4))(3) alloys are found to be the most promising, followed by selected M(1)(Nb/Rh)(BH(4))(4) alloys.
The Journal of chemical physics 08/2009; 131(1):014101. · 3.09 Impact Factor
