Iron incorporated Ni-ZrO2 catalysts for electric power generation from methane

Abstract

On the purpose to perform as functional layer of SOFCs operating on methane fuel, NiFe–ZrO2 alloy catalysts have been synthesized and investigated for methane partial oxidation reactions. Ni4Fe1–ZrO2 shows catalytic activity comparable to that of Ni–ZrO2 and superior to other Fe-containing catalysts. In addition, O2-TPO analysis indicates iron is also prone to coke formation; as a result, most of NiFe–ZrO2 catalysts do not show improved coking resistance than Ni–ZrO2. Anyway, Ni4Fe1–ZrO2 (Ni:Fe = 4:1 by weight) prepared by glycine-nitrate process shows somewhat less carbon deposition than the others. However, Raman spectroscopy demonstrates that the addition of Fe does reduce the graphitization degree of the deposited carbon, suggesting the easier elimination of carbon once it is deposited over the catalyst. Ni4Fe1–ZrO2 has an excellent long-term stability for partial oxidation of methane reaction at 850 °C. A solid oxide fuel cell with conventional nickel cermet anode and Ni4Fe1–ZrO2 functional layer is operated on CH4–O2 gas mixture to yield a peak power density of 1038 mW cm−2 at 850 °C, which is comparable to that of hydrogen fuel. In summary, the Ni4Fe1–ZrO2 catalyst is potential catalyst as functional layer for solid-oxide fuel cells operating on methane fuel.