About this Physics and Astronomy article

First-principles investigations of the Ni3Sn alloy at steam reforming conditions by Souheil Saadi; Berit Hinnemann; Stig Helveg; Charlotte C. Appel; Frank Abild-Pedersen; Jens K. Nørskov is a Physics and Astronomy article available to read on EtoBox.

The structure and surface composition of a Ni 3 Sn alloy at conditions relevant for the steam reforming reaction was investigated using density functional theory calculations. Both the flat Ni 3 Sn(0 0 0 1) surface and a surface with steps in the closed packed direction [1 0 1 0]were considered. The adsorption geometries and energies of the species CO, C, OH and H were calculated. Chemical potentials were used to map out which adsorbates are on the surface under varying conditions. It was found that adsorbates preferably bind to Ni as nearest neighbor with Sn as second-nearest neighbor. The binding energy is slightly stronger than on pure Ni. Adsorbate binding to Sn was found to be very unfavorable. Binding free energies indicate that at high temperature the alloy surface will be predominantly covered by CO and C, and at low temperatures one may find H and almost no OH. Even though the nominal composition of the investigated alloy is Ni 3 Sn, the surface composition may differ significantly depending on temperature and pressure of the gas phase. This effect was investigated by calculating segregation energies both in the absence and in the presence of adsorbates. For the flat surfa

Author

Souheil Saadi; Berit Hinnemann; Stig Helveg; Charlotte C. Appel; Frank Abild-Pedersen; Jens K. Nørskov

Publisher

Elsevier Science; Elsevier ; Elsevier BV (ISSN 0039-6028)

Published

2009

Language

EN

Field

Physics and Astronomy (Physical Sciences)