Catalytic activity improvement for efficient hydrogen oxidation of infiltrated La_0.3Sr_0.7Ti_0.3Fe_0.7O_3-δ anode for solid oxide fuel cell

In this paper, a ceramic perovskite anode for solid oxide fuel cells (SOFCs) is prepared by infiltrating La and Fe co-doped strontium titanium, La_0.3Sr_0.7Ti_0.3Fe_0.7O_3-δ (LSTF0.7) into porous backbone of scandia-stabilized zirconia (ScSZ) and tested in pure H₂ at 700–850 °C. LSTF0.7 crystal exhibits high reduction stability and good compatibility with ScSZ electrolyte under reducing atmosphere. In order to improve the electrocatalytic activity, 15 wt% of CeO₂ and 7 wt% of Ni are infiltrated into the backbone pores respectively, thus forming LSTF0.7-CeO₂ and Ni-CeO₂-LSTF0.7 composite anodes. The cell with LSTF0.7 single anode shows a relatively lower maximal power density (MPD) of 401 mW cm⁻² in H₂ at 800 °C. While the maximal power densities of the cells with LSTF0.7-CeO₂ and Ni-CeO₂-LSTF0.7 composite anodes are 612 mW cm⁻² and 698 mW cm⁻² operated at the same conditions, respectively. The three anode polarization resistances (Rp,a) distinguished from the corresponding full cells are 0.176, 0.086 and 0.076 Ω cm² at 800 °C, respectively. The values of the activation energy (Ea) towards H₂ oxidation for the three anodes can be calculated to be 52.2, 46.0, 43.9 kJ mol⁻¹ based on their respective Rp,a. Therefore, the LSTF0.7-based anodes are considered to be promising alternatives for solid oxide fuel cell applications.