The Performance of Ruddlesden–Popper (R-P) Structured Pr_2–xSr_xNi_0.2Mn_0.8O₄ for Reversible Single-Component Cells

Abstract

In view of high catalytic activity and oxygen vacancy concentration, Ruddlesden−Popper (R-P) structure oxide has been widely used as the electrode material for solid oxide fuel cells (SOFCs). Herein, three R-P structure oxides, Pr 2−x Sr x Ni 0.2 Mn 0.8 O 4 (x = 1, 1.2, and 1.5), are used as the semiconductor materials of single-component cells. The materials for the oxygen side are hybrid oxides consisting of R-P structure oxide and perovskite oxide. The hydrogen side was exposed to the reduction atmosphere before the test, and the perovskite structure disappeared and the lattice parameters of the R-P structure changed, resulting in the formation of a new R-P structure and MnO 2 or NiMn alloy. In addition, Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 and reduced Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 exhibit the most content of oxygen vacancy. For a single-component fuel cell (SCFC), the cell performance increased with the decrease in Pr content. The SCFC composed of Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 shows the highest maximum power densities (P max ), which reached 206.6 mW cm −2 at 700 °C. It is because the reduced Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 has the highest catalytic activity for hydrogen oxidation reaction (HOR). Furthermore, the P max at 700 °C can reach a value of 198.1 mW cm −2 in SOFC mode, and in the case of SOEC mode, the current density at 700 °C is as high as −390.8 mA cm −2 with an applied electrolysis voltage of 1.3 V for the reversible single-component cell (RSCC) with Pr 0.5 Sr 1.5 Ni 0.2 Mn 0.8 O 4 as the semiconducting electrocatalyst.

Evaluating the Effect of B-Site Cation Doping on the Properties of Pr0.4Sr0.5Fe0.9Mo0.1O3 for Reversible Single-Component Cells

“…The details have been described in our previous work. 27 PSCFM11, PSCFM27, or PSNFM27 was first pressed into rectangular bars of 25 × 7.0 × 2.0 mm 3 and then calcined in air at 1250 °C for 6 h. When measuring the conductivities of R-PSCFM11, R-PSCFM27, and R-PSNFM27 in 5% H 2 atmosphere, PSCFM11, PSCFM27, and PSNFM27 were first pretreated in a hydrogen stream at 700 °C for 2 h, then switched to 5% H 2 , and held for 2 h.…”

“…In addition, the electrical conductivities of PSCFM11, PSCFM27, and PSNFM27 in air atmosphere and those of R-PSCFM11, R-PSCFM27, and R-PSNFM27 in 5% H 2 atmosphere were measured by the four-probe method. The details have been described in our previous work . PSCFM11, PSCFM27, or PSNFM27 was first pressed into rectangular bars of 25 × 7.0 × 2.0 mm 3 and then calcined in air at 1250 °C for 6 h. When measuring the conductivities of R-PSCFM11, R-PSCFM27, and R-PSNFM27 in 5% H 2 atmosphere, PSCFM11, PSCFM27, and PSNFM27 were first pretreated in a hydrogen stream at 700 °C for 2 h, then switched to 5% H 2 , and held for 2 h.…”

Enhancing Bifunctional Electrocatalytic Activities of La0.5Sr0.5Co0.2Fe0.8O3 in Reversible Single-Component Cells

“…(1) The morphology of carbonate changes during the electrolysis process. Previous research has found that the morphology of carbonate in RSCC gradually becomes lumpy and flake during the operation process . (2) Carbonate may be partially decomposed during operation .…”

“…Sm 0.2 Ce 0.8 O 2 -(Li/Na) 2 CO 3 (SDC-LN) as an ionic conductor was prepared by ball milling and the weight ratio of SDC and LN was 7:3. The preparation processes of SDC and LN and the fabrication of SCFC and RSCC have been reported in our previous work. , …”

“…The previous experimental research found that SCFC can also electrolyze water, so it can be used as a reversible single-component cell (RSCC). − It is reported that the perovskite oxides such as (Pr, Sr)­(Co, Fe, Mo)­O 3‑δ and (La, Sr)­FeO 3−δ series materials show good catalytic activity for oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR). − Among them, doped (La, Sr)­FeO 3−δ shows good structural stability and electrocatalytic activity for electrode reaction in RSOC . Guan et al synthesized 10%Nb-doped La 0.6 Sr 0.4 FeO 3−δ and used it as an oxygen electrode.…”