Journal of Power Sources, Vol.271, 516-521, 2014
Resistance to sulfur poisoning of the gold doped nickel/yttria-stabilized zirconia with interface oxygen vacancy
The effects of IB metal (Gold, Silver, and Copper) dopants at the triple phase boundary (TPB) on the resistance to sulfur poisoning of the Nickel/Yttria-Stabilized Zirconia (YSZ) with interface oxygen vacancy (denoted as Ni/YSZ-Ov) are studied using the first-principles method based on density functional theory. Models with Au, Ag, Cu dopants at the TPB of Ni/YSZ-Ov are proposed. It is found that the Au dopant prefers to be at the neighbor of the oxygen vacancy site (denoted as NiAu-d/YSZ-Ov) while the Ag, Cu dopants tend to be located at the top Ni layer, which have little effects on the sulfur adsorption at the interface oxygen vacancy site. Compared with Ni/YSZ-Ov, the NiAu-d/YSZ-Ov can not only weaken the sulfur adsorption at the interface oxygen vacancy site, but also restrain the diffusion of sulfur to the interface oxygen vacancy. Instead, the adsorbed S at the oxygen vacancy is more easily to diffuse out of the interface oxygen vacancy site. So we propose that doping Au in Ni at the neighbor of the interface oxygen vacancy site would be good way to increase the resistance to sulfur poisoning of the Ni/YSZ-Ov anode. (C) 2014 Elsevier B.V. All rights reserved.
Keywords:Solid oxide fuel cell;Sulfur poisoning;Nickel/yttrium-stabilized zirconia anode;Oxygen vacancy