Direct-methane solid oxide fuel cells with an in situ formed Ni–Fe alloy composite catalyst layer over Ni–YSZ anodes

Coking on Ni surfaces limits the direct application of methane-based fuels in SOFCs with Ni-cermet anodes. Loading an anodic catalytic layer with a high catalytic activity for CH₄ conversion can effectively protect the Ni-based anode from coking and increase the cell durability. In this work, a Ni–Fe alloy composite catalyst was prepared by reducing perovskite La_0.7Sr_0.3Fe_0.8Ni_0.2O_3-δ (LSFN) and then evaluating its catalytic activity in the partial oxidation of CH₄. The catalyst was applied on a conventional Ni–8 mol.% Y-stabilized ZrO₂ (YSZ) anode for methane SOFCs using two methane-containing fuels (97% CH₄–3% H₂O and 30% CH₄–70% air). The catalyst-modified cells showed much higher performances and durability than the conventional cell using a Ni–YSZ anode, indicating the potential application for direct-methane SOFCs.