Behavior of nickel aluminate spinel under high-temperature fuel cell anode conditions.

摘要

This thesis reports an investigation of nickel aluminate spinel which could find application as a reforming catalyst in internal reforming fuel cells. The electrical conductivity of NiAl₂O₄ is in the order of 10–3–10–4 S/cm under oxidizing environment. And it is about 10–5 S/cm under reducing conditions. It was found that under reducing conditions, NiAl ₂O₄ was partially reduced to form monodispersed metallic nickel as nanoparticles. The activation rate constant of this reduction process was found to be k = 1.78 * 104 exp(-72400/RT) m3/(mol-min). After in-situ reduction, NiAl₂O₄ has good catalytic activity for methane steam reforming under reducing conditions. A 10-day stability test was also performed. The material showed relative stable catalytic activity during the 10-day test.