Combined DFT and Microkinetic Modeling Study of Hydrogen Oxidation at the Ni/YSZ Anode of Solid Oxide Fuel Cells

The oxidation mechanism of H 2 fuel at the three-phase boundary of Ni/YSZ has been investigated under experimental solid oxide fuel cell conditions by a combination of density functional theory and microkinetic modeling. It is shown that the O migration pathway is 2–4 orders of magnitude faster than the H spillover and OH migration pathways. Bulk oxygen diffusion in YSZ is rate-limiting at low temperatures, and H transfer from Ni to YSZ to form water becomes rate-limiting at high temperatures.