Cerium effect on the phase structure, phase stability and redox properties of Ce-doped strontium ferrates

Citrate–nitrate auto-combustion synthesis of perovskite-type nanopowders: A systematic approach

“…It is plausible to argue that segregation at high F/O ratios may be favoured when the concentration of the dopant cation approaches the solubility limit in the perovskite. The solubility limit of cerium in SrFeO 3 is around 15 mol% and for higher dopant content cerium segregates as CeO 2 37 ; the solubility limit of strontium in LaCoO 3 is ≤50 mol%, whereas for higher dopant content the rhombohedral Sr-doped LaCoO 3 transforms in the cubic La-doped SrCoO 3 . 52 In this work, for CO samples, a Sr-rich phase like SrLaCoO 4 segregates (Fig.…”

Sucrose-Assisted Solution Combustion Synthesis of Doped Strontium Ferrate Perovskite-Type Electrocatalysts: Primary Role of the Secondary Fuel

“…The main requirements of electrode materials are (i) to be able to adsorb oxygen from the air and catalytically reduce it (oxygen reduction reaction) or to evolve oxygen and catalytically oxidize the fuel (oxygen evolution reaction), (ii) to possess high mixed ionic and electronic conductivity, (iii) to be highly compatible with the electrolyte in terms of thermal expansion coefficient (TEC), to avoid detrimental effects on the performances and failures in long-term operations.SrFeO 3-δ is a perovskite-type mixed oxide where iron has the expected oxidation state of +4, whereas in most ABO 3 perovskites, like pure and doped LaFeO 3 , the common oxidation state at B-site is +3 [38]. This compound is able to accommodate a large range of oxygen deficiencies, so that some Fe 3+ , with a larger ionic radius, is formed to restore the electroneutrality [40,41]. The oxygen Catalysts 2020, 10, 134 3 of 19 non-stoichiometry is an important factor to achieve high oxygen adsorption, oxygen mobility, and high ionic conductivity [41,42].…”

A Cobalt‐Free Multi‐Phase Nanocomposite as Near‐Ideal Cathode of Intermediate‐Temperature Solid Oxide Fuel Cells Developed by Smart Self‐Assembly

“…The phase compositions of the various materials were first examined by room‐temperature X‐ray diffraction (XRD). SF exhibited a single‐phase as reported elsewhere (Figure S1, Supporting Information) . Based on Rietveld refinement, the material took a tetragonal I4/mmm structure and the lattice parameters of SF are a = b = 10.907 Å, c = 7.671 Å.…”

“…The fitting parameters of R wp = 5.56%, R p = 4.12%, and χ 2 = 3.549 confirm the reliability of the Rietveld refinement, indicating a reliable fitting of the various components in the SCFN2 composite. The crystal structures of T‐SCFN and RP‐SCFN match well with tetragonal SF and Sr 4 Fe 3 O 10– δ (RP‐SF), respectively, while their lattice parameters are slightly different, which may attribute to the partial substitution of SF and RP‐SF with Ce and Ni elements. Based on the nominal composition of Sr 0.9 Ce 0.1 Fe 0.8 Ni 0.2 O 3– δ , the mass fractions of CeO 2 and NiO in SCFN2 are ≈8.72 wt% and 7.57 wt%, respectively, which are higher than those of refined results (3.70 wt% and 5.80 wt%), further confirming the presence of Ce and Ni elements in the two major phases (T‐SCFN and RP‐SCFN).…”

“…SF exhibited a single-phase as reported elsewhere ( Figure S1, Supporting Information). [24] Based on Rietveld refinement, the material took a tetragonal I4/mmm structure and the lattice parameters of SF are a = b = 10.907 Å, c = 7.671 Å. As to SCFN2, it is actually a multiphase mixture (composite).…”