Oxygen nonstoichiometry and defect chemistry of the mixed conductor La0.9Ca0.1FeO3−δ at low oxygen partial pressure

Hydrogen‐assisted Carbon Dioxide Thermochemical Reduction on La0.9Ca0.1FeO3−δ Membranes: A Kinetics Study

“…The cation ratios are verified by EDX measurement, and the lattice structure is shown in our previous work. [30] The acceptor-doped LCF-91 exhibits good oxygen permeability at elevated temperatures, [63] and stable perovskite structure can be maintained with low Ca substitution. [64] The grain sizes of the as-fabricated membranes are in the order of magnitudes of 1 mm.…”

Toward enhanced hydrogen generation from water using oxygen permeating LCF membranes

“…Ca-substitution in the La site of LaFeO 3 (LFO) lattice leads to charge compensation by either forming oxygen vacancies or oxidizing Fe 3+ to Fe 4+ , hence, decreasing oxygen permeation barriers. 27 However, as Ca is substituted, phase separation might occur, which leads to a mixture of perovskite (La 1Àx Ca x FeO 3 ), Grenier (LaCa 2 Fe 3 O 8 ) and brownmillerite (Ca 2 Fe 2 O 5 ) phases. 28 The Goldschmidt tolerance factor, T G , is often used to identify whether the chemical compound can form a stable perovskite lattice, and the tolerance factor for La x Ca 1Àx FeO 3Àd can be calculated as Under operating conditions such as high temperature and reducing gases, new phases or element segregations may occur on the perovskite surface.…”

Mixed ionic-electronic conducting (MIEC) membranes for thermochemical reduction of CO2: A review

“…Geary and Adler [142] used coulometric titration cell to derive the equilibrium oxygen nonstoichiometry and charged species concentration based on the current response. Figure 12 shows the charged species concentrations at equilibrium for LCaF-91 at 990 o C calculated based on the parameters reported in [142]. Electron holes dominate the electronic conduction at high oxygen partial pressure, while electrons dominate at low oxygen partial pressures.…”