Molecular dynamics simulations, used in conjunction with a set of Born model potentials, have been employed to study oxygen transport in tetragonal La2NiO4+d. We predict an interstitialcy mechanism with an activation energy of migration of 0.51 eV in the temperature range 800–1100 K. The simulations are consistent with the most recent experiments. The prevalence of oxygen diffusion in the a–b p...

La2NiO4+d (LNO214) is a potential intermediate temperature solid oxide fuel cell (IT-SOFC) cathodematerial which belongs to the Ruddlesden–Popper (RP) structure series An+1BnO3n+1. There is interest in this material as it offers a way to avoid Sr segregation and associated degradation, as LNO214 can take in oxygen interstitials and become catalytically active without A-site doping. While the bu...

To understand ultra-fast oxygen reduction reaction kinetics near La0.8Sr0.2CoO3/(La0.5Sr0.5)2CoO4 (LSC113/214) interface, a combination of in-situ scanning tunneling spectroscopy and focused ion beam milling was used to study the local electronic structure near LSC113/214 interface at elevated temperature and in oxygen. The electronic activation of LSC214 by the coupling with LSC113, concurrent...

While solid-state NMR spectroscopic techniques have helped clarify the local structure and dynamics of ionic conductors, similar studies of mixed ionic-electronic conductors (MIECs) have been hampered by the paramagnetic behavior of these systems. Here we report high-resolution (17)O (I = 5/2) solid-state NMR spectra of the mixed-conducting solid oxide fuel cell (SOFC) cathode material La2NiO4+...

Oxygen nonstoichiometry, electrical conductivity and thermal expansion of La2-xSrxNiO4- phases with high levels of strontium substitution (1 ≤ x ≤ 1.4) have been investigated in air and oxygen atmosphere in the temperature range 20-1050 °C. These phases retain the K2NiF4-type structure of La2NiO4 (tetragonal, space group I4/mmm). The oxygen vacancy fraction was determined independently from th...

Oxygen nonstoichiometry, electrical conductivity and thermal expansion of La2-xSrxNiO4- phases with high levels of strontium substitution (1 ≤ x ≤ 1.4) have been investigated in air and oxygen atmosphere in the temperature range 20-1050 °C. These phases retain the K2NiF4-type structure of La2NiO4 (tetragonal, space group I4/mmm). The oxygen vacancy fraction was determined independently from th...

Oxygen surface exchange properties of lanthanum nickelates La2NiO4+?, La3Ni2O7-? and La4Ni3O10-? (LNOs) have been investigated using the Pulsed Isotope 18O/16O Exchange (PIE) technique in temperature range 300–700 ?°C. The evaluation oxygen rate from these was conducted by measurement isotope fractions 18O2, 16O18O, 16O2 effluent pulse at exhaust reactor with a packed bed. rates heterogenous (r...

The La2NiO4 film was synthesized on the 304 stainless steel (SS) mesh. The hydrogen reduction of La2NiO4 generated homogeneous nanocatalyst particles (probably Ni/La2O3) over which methane was cracked, producing carbon nanotubes/microfibers and hydrogen. The carbon nanotubes/microfibers were strongly bonded to the SS mesh. It was observed that the methane conversion always reached its maximum a...