Oxygen isotope exchange and diffusion in LnBaCo2O6−δ (Ln = Pr, Sm, Gd) with double perovskite structure

Oxygen diffusion and surface exchange kinetics for the mixed-conducting oxide La0.6Sr0.4Co0.8Fe0.2O3-δ

“…The values of activation energy for the exchange and diffusion processes are listed in Table 1. It should be noted that relatively high values of oxygen diffusion and exchange coefficients for the studied La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ oxide are comparable with the values for barium praseodymium cobaltite [29] and are greater by the value of magnitude than those for lanthanum strontium manganite [22]. Therefore, it may be assumed that La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ is a perspective oxide for the SOFC cathode materials, because of its high values of exponents in the equation for oxygen exchange reaction and good stability in the reducing atmosphere.…”

“…Figs. 9, 10 illustrate the temperature dependencies of oxygen exchange coefficient and oxygen diffusion coefficient, respectively, in comparison with literary data for different oxides [22,[26][27][28][29]. The values of activation energy for the exchange and diffusion processes are listed in Table 1.…”

Rate-Determining Steps of Oxygen Surface Exchange Kinetics on Sr2Fe1.5Mo0.5O6−δ

“…oxygen diffusion coefficients for Sr2Fe1.5Mo0.5O6−δ oxide were obtained; these values were comparable to the values for praseodymium-barium double cobaltite and exceeded the lanthanum-strontium manganite by more than an order of magnitude. [37,[42][43][44][45][46].…”

“…To reduce the contribution of this process to the polarization resistance of the oxygen electrode, it is necessary to impregnate the Sr2Fe1.5Mo0.5O6−δ electrode with active oxides, for example, praseodymium oxide [19], or add mixed conductors to SFM, for example, based on cerium oxide [9,20], or increase the concentration of electronic charge carriers in Sr2Fe1.5Mo0.5O6−δ, for example, doping with heterovalent cations. for some oxides [37,42,[44][45][46][47].…”

“…Figure 6. Temperature dependences of the oxygen surface exchange coefficient (A) and the oxygen diffusion coefficient (B) for oxides[37,[42][43][44][45][46].…”