IFISUR   23398
INSTITUTO DE FISICA DEL SUR
Unidad Ejecutora - UE
artículos
Título:
A theoretical view of 1,3-butadiene selective hydrogenation towards cis-2-butene on Pd-Ni layered catalyst
Autor/es:
G. GÓMEZ; G. F. CABEZA; N. J. CASTELLANI; P. G. BELELLI
Revista:
APPLIED SURFACE SCIENCE
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2015 vol. 353 p. 820 - 828
ISSN:
0169-4332
Resumen:
The production of cis-2-butene (cis-2B) on Pd/Ni3(111) bimetallic model was evaluated considering two possible reactions: through the hydrogenation of 1,3-butadiene (13BD) adsorbed on a cis-geometry site and through the isomerization of trans-2-butene (trans-2B). For that purpose, density functional theory (DFT) calculations were performed following the Horiuti-Polanyi mechanisms. In the hydrogenation, two competitive pathways produce cis-2B and trans-2B from 13BD species adsorbed on di-p-cis and 1,2,3,4-tetra-s sites, respectively. The cis-2B is obtained with smaller energy requirements than the trans-2B isomer in spite of the adsorption of 13BD on the di-p-cis site is 0.10 eV less stable than on the 1,2,3,4-tetra-s site. On the other hand, the trans-2B previously formed could be isomerized to cis-2B, and vice versa, trough the 2-butyl intermediates, but the elevated energetic barriers to hydrogenate/dehydrogenate both 2B isomers would avoid these processes. In fact, the dehydrogenation reaction is the limiting step of the latter. From these results, we infer that on the Pd/Ni3(111) surface the cis-2B isomer is easier to be formed via the 13BD hydrogenation on cis-geometry site than via the trans/cis isomerization of 2B.