Insights on a Ruddlesden-Popper phase as an active layer for a solid oxide fuel cell fed with dry biogas

Solid oxide fuel cell (SOFC) is a mature opportunity for producing power energy in remote areas likeislands, where access to the electrical grid is not favoured, and gas distribution is the only viableapproach. In this context, generally, biogas represents the most convenient fuel resources in these areas.However, the direct use of biogas in SOFCs is still an issue to be solved due to its negative effect on theconventional Ni-YSZ anode. In this study, to overcome this issue, we suggested using a protective layercoated on the anode of a commercial SOFC. A nickel manganite showing mixed ionic and electronicconductivity tailored specifically for this approach was investigated. The preliminary characterisationsshowed that the formation of a Ruddlesden-Popper (RP) n ¼ 1 structure supporting fine encapsulatedparticles based on Ni was formed around 800 C in consequence of the reducing environment. Theelectrochemical experiments carried out for 270 h demonstrated for the coated cell significant stability inthe presence of dry biogas, albeit an ageing effect was noticed in the electrical percolation of both cellelectrodes. The post mortem analyses revealed an attractive redox property for the nickel manganite,which partially returned to the RP n ¼ 2 phase. Moreover, the absence of carbon deposits on the anodesuggests possible applications for this approach.