We present density-functional theory calculations of the chemisorption of atomic species O, S, C, H and reaction intermediates OH, SH, and CHn (n = 1, 2, and 3) on M/Ni alloy model catalysts (M= Bi, Mo, Fe, Co, and Cu). The activity of the Ni alloy catalysts for solid-oxide fuel cell (SOFC) anode oxidation reactions is predicted, based on a simple descriptor, i.e., the binding energy of oxygen. First, we find that the binding of undesirable intermediates, such as C and S, can be inhibited and the catalytic activity of planar Ni-based anodes can be tuned towards oxidation by selectively forming a bimetallic surface alloy. In particular, Cu/Ni, Fe/Ni, and Co/Ni anode catalysts are found to be most active towards anode oxidation. On the
other hand, the Mo/Ni alloy surface is predicted to be the most effective catalyst in terms of inhibiting the deposition of C and S (while still preserving relatively high catalytic activity). The formation of a surface alloy, which has the alloy element enriched on the topmost surface, was found to be critical to the activity of the Ni alloy catalysts.
Revised: August 31, 2015 |
Published: May 15, 2011
Citation
An W., D. Gatewood, B.I. Dunlap, and C. Turner. 2011.Catalytic Activity of Bimetallic Nickel Alloys for Solid-Oxide Fuel Cell Anode Reactions from Density-Functional Theory.Journal of Power Sources 196, no. 10:4724-4728. doi:10.1016/j.jpowsour.2011.01.007