Applying high efficiency internal reforming catalyst for direct low concentration coal mine methane solid oxide fuel cells

Abstract

Solid oxide fuel cells (SOFCs) are green and efficient power generation devices, which can efficiently utilize the abundant low concentration coal mine methane (LC-CMM), and play an important role in energy saving and emission reduction. However, there are still challenges need to be addressed, such as low conversion efficiency and deposit carbon. In this work, a Sr2Fe1.4Ni0.1Mo0.5O6-δ-Gd0.1Ce0.9O2-δ (SFNM-GDC) internal reforming catalyst is prepared, generating abundant oxygen vacancies with in situ precipitates Fe–Ni alloys in the reducing atmosphere, leading to improved methane reforming efficiency and carbon deposition resistance. The results show that the cell exhibits excellent electrochemical performance with the internal reforming catalyst, with the maximum power density (Pmax) of 1212 mW cm−2 and 980 mW cm−2 at 800 °C with H2 and LC-CMM, respectively, corresponding to polarization impedances of 0.16 Ω cm2 and 0.47 Ω cm2. More importantly, the single cell combining SFNM-GDC reformed layer can maintain stable performance for 100 h at 700 °C under the atmosphere of LC-CMM. These results highlight that the reformed layer enhances CH4 reforming, optimizes electrochemistry and increases resistance to carbon deposition.