Ab initio analysis of sulfur tolerance of Ni, Cu, and Ni–Cu alloys for solid oxide fuel cells

Interactions between sulfur and Ni1−xCux (x = 0.00, 0.25, 0.50, 0.75, and 1.00) were examined by a first-principles analysis based on density functional theory (DFT) calculations to provide a scientific basis for intelligent design of sulfur-tolerant anode materials for solid oxide fuel cells (SOFCs). Examination of slab models with three and five atomic layers for Ni and Cu (1 1 1) surfaces indicates that sulfur species may adsorb on four types of sites: atop, bridge, hcp hollow, and fcc hollow, among which the fcc-hollow centers are the most energetically favorable. The adsorption energy of sulfur on Ni is approximately 20% higher than that on Cu for both unrelaxed and relaxed five-layer surface models, which is qualitatively in good agreement with experimental observations. Using two active sites at three-fold hollow sites, the adsorption energy for sulfur on Ni1−xCux is predicted as a function of the alloy composition. Alloying Ni with Cu improves sulfur tolerance, however not to the degree of pure Cu.

[1]  Zhe Cheng,et al.  A solid oxide fuel cell operating on hydrogen sulfide (H2S) and sulfur-containing fuels , 2004 .

[2]  J. Demuth,et al.  Crystallographic Dependence of Chemisorption Bonding for Sulfur on (001), (110), and (111) Nickel , 1974 .

[3]  Nguyen Q. Minh,et al.  Science and Technology of Ceramic Fuel Cells , 1995 .

[4]  Meilin Liu,et al.  A mechanistic study of H2S decomposition on Ni- and Cu-based anode surfaces in a solid oxide fuel cell , 2006 .

[5]  J. Hafner,et al.  Density-functional study of the adsorption of benzene on the (1 1 1), (1 0 0) and (1 1 0) surfaces of nickel , 2001 .

[6]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[7]  Axel D. Becke,et al.  Density-functional thermochemistry. I. The effect of the exchange-only gradient correction , 1992 .

[8]  G. Hutchings,et al.  Ab initio simulation of the interaction of hydrogen with the {111} surfaces of platinum, palladium and nickel. A possible explanation for their difference in hydrogenation activity , 2000 .

[9]  Martin Head-Gordon,et al.  Quadratic configuration interaction. A general technique for determining electron correlation energies , 1987 .

[10]  G. Kresse,et al.  Ab initio molecular dynamics for liquid metals. , 1993 .

[11]  Hong Yang,et al.  Adsorption of SH and OH and coadsorption of S, O and H on Ni(111) , 1997 .

[12]  William D. Callister,et al.  Materials Science and Engineering: An Introduction , 1985 .

[13]  J. Hafner,et al.  First-principles study of the adsorption of atomic H on Ni (111), (100) and (110) , 2000 .

[14]  Effect of Sn on the Reactivity of Cu Surfaces , 2004 .

[15]  A. Becke.  Density-functional thermochemistry. II: The effect of the Perdew-Wang generalized-gradient correlation correction , 1992 .

[16]  Masayuki Dokiya,et al.  SOFC system and technology , 2002 .

[17]  Jens K. Nørskov,et al.  Theoretical surface science and catalysis—calculations and concepts , 2000 .

[18]  Kresse,et al.  Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. , 1996, Physical review. B, Condensed matter.

[19]  A. Becke.  Density-functional thermochemistry. III. The role of exact exchange , 1993 .

[20]  R J Gorte,et al.  Direct oxidation of sulfur-containing fuels in a solid oxide fuel cell. , 2001, Chemical communications.

[21]  S. Overbury,et al.  Structure analysis of S adsorbed on Ni(111) by low energy Li+ ion scattering , 1992 .

[22]  G. Kresse,et al.  From ultrasoft pseudopotentials to the projector augmented-wave method , 1999 .

[23]  H. Monkhorst,et al.  SPECIAL POINTS FOR BRILLOUIN-ZONE INTEGRATIONS , 1976 .

[24]  M. W. Roberts,et al.  Chemistry of the metal-gas interface , 1978 .