B-Site Super-Excess Design Sr₂V_0.4Fe_0.9Mo_0.7O_6−δ-Ni_0.4 as a Highly Active and Redox-Stable Solid Oxide Fuel Cell Anode

Abstract

In-situ exsolution type perovskites as solid oxide fuel cell (SOFCs) anode materials have received widespread attention because of their excellent catalytic activity. In this study, excessive NiO is introduced to the Sr2V0.4Fe0.9Mo0.7O6−δ (SVFMO) perovskite with the B-site excess design, and in-situ growth of FeNi3 alloy nanoparticles is induced in the reducing atmosphere to form the Sr2V0.4Fe0.9Mo0.7O6−δ-Ni0.4 (SVFMO-Ni0.4) composite anode. Here, with H2 or CH4 as SOFCs fuel gas, the formation of FeNi3 nanoparticles further enhances the catalytic ability. Compared with SVFMO, the maximum power density (P max) of Sr2V0.4Fe0.9Mo0.7O6−δ-Ni0.4 (SVFMO-Ni0.4) increases from 538 to 828 mW cm–2 at 850 °C with hydrogen as the fuel gas, and the total polarization resistance (R P) decreases from 0.23 to 0.17 Ω cm2. In addition, the long-term operational stability of the SVFMO-Ni0.4 anode shows no apparent performance degradation for more than 300 h. Compared with SVFMO, the P max of SVFMO-Ni0.4 increases from 138 to 464 mW cm–2 with methane as fuel gas, and the R P decreases from 1.21 to 0.29 Ω cm2.

Realizing Efficient Activity and High Conductivity of Perovskite Symmetrical Electrode by Vanadium Doping for CO2 Electrolysis

“…The notable increase in conductivity can be attributed to the abundance of small polaron pairs present in the SFMV 0.1 sample, resulting from the complex valence state of Fe/V/Mo cations of the B-site. This accumulation of electron carriers is consistent with the XPS analyses. , Figure S5a displays the electrical conductivity of SFMV 0.1 measured in air. A decrease in conductivity at temperatures above 600 °C is likely due to the superfluous oxygen vacancy concentration. , At 800 °C, the conductivity of SFMV 0.1 reaches 14.28 S cm –1 in air.…”

Ni-Substituted Sr2FeMoO6−δ as an Electrode Material for Symmetrical and Reversible Solid-Oxide Cells

“…Furthermore, it is noteworthy that with the Ni doping content of x elevated to 0.4 (Figure S1), the diffraction peak gradually shifts toward a higher angle, indicating a slight lattice shrinkage. The results are likely attributed to two factors: first, the doped Ni ionic radius is smaller than that of the Fe ion; second, due to the partial substitution of Mo with Ni, the changes in the conduction orbitals of Fe and Mo are maybe closer to each other. − The unbalanced positive charge in SFM could also be inhibited by thermal treatment in a reducing atmosphere, and it is confirmed in Figure b that the SrMoO 4 phase almost disappears after reduction in the 10% H 2 /N 2 at 850 °C for 10 h. It should be noticed that the mixed phases containing a metallic phase, RP phase Sr 3 FeMoO 7−δ (JCPDS 52-1715), and perovskite phase are observed in the case of SFN 0.35 M after reduction treatment. The metallic phase, which can be well identified as an Fe–Ni alloy (JCPDS 65-3244), can form a solid solution with a floating content of Fe and Ni.…”

Probing metal/high-entropy perovskite heterointerfaces for efficient and sustainable CO2 electroreduction

“…Fig. 1b illustrates the XRD results for reduced SFVMNT, which was obtained by annealing in a H 2 atmosphere at 850 °C for 1 h. 32,33 It is clear that the scheelite phase transforms into a cubic perovskite structure (PDF#05-0634), with a space group of Pm 3 m and lattice parameters of a = b = c = 3.905 Å (Fig. 1c).…”