X-ray photoelectron spectroscopic study of impregnated La_0.4Sr_0.6Ti_0.8Mn_0.2O_3±d anode material for high temperature-operating solid oxide fuel cell

In this study, the chemical states of a powder type and an impregnated type of the La_0.4Sr_0.6Ti_0.8Mn_0.2O_3±d (LSTM) oxide system were investigated along with its electrical conductivities in order to apply these materials as alternative anode materials for high temperature-operating Solid Oxide Fuel Cells (HT-SOFCs). The Ni/8YSZ samples with LSTM impregnated into the pores created by partially removing nickel, Ni/8YSZ (Ni (R)/8YSZ), showed much higher electrical conductivity values than those of unimpregnated Ni/8YSZ (Ni (E)/8YSZ) samples under dry H₂ fuel condition. Reduction of Mn⁴⁺ to Mn³⁺ was observed when LSTM was reduced. Additional reduction properties of Mn²⁺ from Mn³⁺ and satellite peaks were found when impregnated LSTM was coated onto a Ni/8YSZ substrate. The reduction of the charge state of Ti contained in LSTM showed the same behavior as the reduction property of Mn. However, a satellite peak identified as metal Ti was only observed when impregnated LSTM was coated on a selectively Ni-removed Ni/8YSZ (Ni (R)/8YSZ) substrate.