resumo
We report a comparative periodic density functional theory study of the reaction of water dissociation on five platinum surfaces, e.g., Pt(111) Pt(100), Pt(110), Pt(211), and Pt(321). These surfaces were chosen to study the surface structural effects in the reaction of water dissociation. It was found that water molecules adsorb stronger on surfaces presenting low coordinated atoms in the surface. In the cases of the stepped Pt(110) and kinked Pt(321) surfaces, the activation energy barriers are smaller than the adsorption energies for the water molecule on the corresponding surfaces. Therefore, the calculations suggest that the dissociation reaction will take place preferentially at corner or edge sites on platinum particles with the (110) orientation. The inclusion of the results obtained in this work in previous derived BEP relationships confirms that the adsorption energy of the reaction products arises as the most appropriate descriptor for water dissociation on transition metal surfaces.
palavras-chave
GAS-SHIFT REACTION; TOTAL-ENERGY CALCULATIONS; AUGMENTED-WAVE METHOD; LOW-TEMPERATURE; CATALYTIC-ACTIVITY; PARTICLE-SIZE; SUPPORTED CU; BASIS-SET; IN-SITU; METAL
categoria
Chemistry; Physics
autores
Fajin, JLC; Cordeiro, MNDS; Gomes, JRB
nossos autores
José R. B. Gomes
Investigador PrincipalProjectos
Computational Design of new catalysts for the water gas shift reaction (PTDC/QUI-QUI/117439/2010)
agradecimentos
Thanks are due to Fundacao para a Ciencia e Tecnologia (FCT), Lisbon, Portugal, and to FEDER for financial support to REQUIMTE (projects Pest-C/EQB/LA0006/2013 and NORTE-07-0124-FEDER-000067-NANOCHEMISTRY) and to CICECO (project Pest-C/CTM/LA0011/2013) and for Programa Investigador FCT. This work has been supported also by FCT through project PTDC/QUI-QUI/117439/2010 (FCOMP-01-0124-FEDER-020977) cofinanced by Programa COMPETE. J.L.C.F. acknowledges FCT for the grant SFRH/BPD/64566/2009 cofinanced by the Fundo Social Europeu (FSE).