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The in situ exsolution technique of nanoparticles has brought new opportunities for the utilization of perovskite‐based catalysts in solid oxide cells. However, the lack of control over the structural evolution of host perovskites during the promotion of exsolution has restricted the architectural exploitation of exsolution‐facilitated perovskites. In this study, we strategically broke the long‐standing trade‐off phenomenon between promoted exsolution and suppressed phase transition via B‐site supplement, thus broadening the scope of exsolution‐facilitated perovskite materials. Using carbon dioxide electrolysis as an illustrative case study, we demonstrate that the catalytic activity and stability of perovskites with exsolved nanoparticles (P‐eNs) can be selectively enhanced by regulating the explicit phase of host perovskites, accentuating the critical role of the architectures of perovskite scaffold in catalytic reactions occurring on P‐eNs. The concept demonstrated could potentially pave the way for designing the advanced exsolution‐facilitated P‐eNs materials and unveiling a wide range of catalytic chemistry taking place on P‐eNs. [ABSTRACT FROM AUTHOR]

Symmetrical solid oxide fuel cell (SOFC) adopting the same material at both electrodes is potentially capable of promoting thermomechanical compatibility between near components and lowering stack costs. In this paper, MnCr 2 O 4 –Gd 0.1 Ce 0.9 O 2-δ (MCO-GDC) composite electrodes prepared by co-infiltration method for symmetrical electrolyte supported and anode supported solid oxide fuel cells are evaluated at a temperature range of 650–800 °C in wet (3% H 2 O) hydrogen and air atmospheres. Without any alkaline earth elements and cobalt, the co-infiltrated MCO-GDC composite electrode shows excellent activity for oxygen reduction reaction but mediocre activity for hydrogen oxidation reaction. With MCO-GDC as the cathode, the Ni-YSZ (Y 2 O 3 stabilized ZrO 2) anode supported asymmetrical cell demonstrates a peak power density of 665 mW cm−2 at 800 °C. The above results suggest MCO-GDC is a promising candidate cathode material for solid oxide fuel cells. • MnCr 2 O 4 is chemically stable at typical dual atmospheres of SOFC. • Co-infiltration promotes the performance of MnCr 2 O 4 -GDC composite electrode. • MnCr 2 O 4 -GDC exhibits reasonable activity as cathode. • Anode supported cell achieves a peak power density of 665 mW cm−2 at 800 °C. [ABSTRACT FROM AUTHOR]

Sb 1-x -Ag x ( x  = 0.1, 0.2, 0.3) alloys, with a lower melting point and a higher density than Sb, are used as anode for tubular 8 mol% yttria stabilized zirconia supported direct carbon solid oxide fuel cells which are prepared through a slurry-casting and co-sintering method. The initial performance of alloy anode cells is lower than that of Sb anode cell, indicating that the addition of Ag has negative effects on the electrochemical reaction between Sb and oxygen ions. After running at different current density from small value until 0.5 A cm −2 for several hours at 750–800 °C, the final performance is very close to that of Sb anode cell. The energy dispersive spectroscopy results and scanning electron microscopy examination of tested cells reveal that a quasi-layered structure instead of a uniform distribution of Sb and Ag is formed in the anode. The Sb and Ag inter-diffusion between carbon-reduced Sb phase and Sb-Ag solution phase is not fast enough to from a uniform phase, thus the original uniformly distributed Sb-Ag solution is gradually replaced by a gradient distribution in which the Ag concentration is from low to high along the gravity direction. [ABSTRACT FROM AUTHOR]

In LaNbO 4 , Sm, Gd and Yb were investigated as substitutes to enhance its ion conductivity, for its application in solid oxide fuel cell. La 0.9 M 0.1 NbO 4 (M = Sm, Gd, Yb) was prepared via a solid–state reaction route and single phase was attained by calcining the constituent oxides at 1200 °C for 5 h. The total conductivity of LaNbO 4 was increased by partly replaced La with Sm, Gd and Yb, due to the muti-valences of the substitutions. The highest conductivity (1.76 × 10 −4 S cm −1 ) was achieved for La 0.9 Sm 0.1 NbO 4 at 800 °C in wet air, more than one order higher compared to that of LaNbO 4 . The introduction of Sm, Gd or Yb also slightly increased the ion transport number of LaNbO 4 , indicating that the increase of the total conductivity was mainly contributed by the enhanced ion conductivity, which was beneficial for its application as a pure ion conductor. [ABSTRACT FROM AUTHOR]

Nanostructured La 0.8 Sr 0.2 Co 0.8 Ni 0.2 O 3-δ (LSCN) based Gd 2 O 3 -doped CeO 2 (GDC) oxygen electrodes are prepared by impregnation method for intermediate temperature solid oxide electrolysis cell (SOEC) for efficient hydrogen production. The microstructure features and the electrochemical performance of the impregnated LSCN-GDC oxygen electrodes with various LSCN loadings are evaluated and investigated. Electrochemical tests show that the impregnated LSCN-GDC oxygen electrodes present great enhancement of oxygen evolution performance, due to the good nanoparticle LSCN dispersion on the GDC scaffold surface to maximize the active reaction sites. The cell with 30 wt% LSCN loaded LSCN-GDC as the oxygen electrode presents a polarization resistance of 0.072 Ω cm 2 at 800 °C with 60 vol% absolute humidity (AH), only about half of that for the screen-printed LSCN electrode. The hydrogen production rate is 484 mL cm −2 h −1 at 750 °C at 1.5 V with 60 vol%AH. For stability test in galvanostatic SOEC operation up to 100 h, the solution impregnated cell shows a very stable performance without obvious degradation. [ABSTRACT FROM AUTHOR]

Direct carbon solid oxide fuel cells (DC-SOFCs) with a liquid Sb anode have many advantages over other types of SOFCs; however, their electrolyte faces corrosion by liquid Sb and Sb 2 O 3. To evaluate the tolerance of the electrolyte to the liquid Sb and Sb 2 O 3 , 8 mol.% Y 2 O 3 –ZrO 2 electrolyte (YSZ) discs are prepared and evaluated at 750 °C for up to 100 h in both chemical and electrochemical modes, simulating DC-SOFC operating conditions. In the chemical mode, the corrosion by liquid Sb causes Y dissolution from YSZ into the liquid Sb, while the YSZ experiences a phase transformation from cubic to tetragonal structure and grain boundary crack on the surface. Liquid Sb 2 O 3 is more corrosive than liquid Sb, penetrating additionally the grain boundaries into a depth around 15 μm. In the electrochemical mode, liquid Sb is separated from YSZ by a layer (~150 μm) of liquid Sb 2 O 3 formed during cell operation. The liquid Sb 2 O 3 layer so formed corrodes YSZ in the same way as in the chemical mode, but the corrosion is intensified with the presence of a current, resulting in a top porous layer (~15 μm) on YSZ surface with a grain boundary penetration layer (~100 μm) underneath. • Both chemical and electrochemical corrosion of YSZ electrolyte were studied. • Liquid Sb (Sb 2 O 3) dissolves Y element out of from YSZ electrolyte. • Liquid Sb 2 O 3 penetrated grain boundaries and was more corrosive than liquid Sb. • Applied current intensified YSZ corrosion by liquid Sb 2 O 3. [ABSTRACT FROM AUTHOR]

This study analyzed the influence of channel resistance, inlet flow rate, manifold depth and other related parameters on the gas distribution uniformity and pressure drop in an external 20-cell solid oxide fuel cell stack by computational fluid dynamics (CFD) technique. It provides a basis for determining the physical and geometric parameters of the stack. Furthermore, the flared inlet tube structure shows the effect of controlling the initial velocity of gas inflow and buffering; the flared outlet tube structure has the benefit of reducing the local pressure loss and the pressure drop. Combined with the perforated sheet structure, the gas in the inlet manifold is redistributed to improve the uniformity of gas flow. Compared with the basic model, the pressure drop of perforated sheet stack was reduced by 17.6% from 349.5 Pa to 288.5 Pa, and the gas flow uniformity index of that was reduced from 4.06% to 0.22%. • The physical and geometric parameters of a 20-cell SOFC stack are studied. • The diameter of inlet and outlet flared tubes are optimized. • A perforated sheet is designed to improve the flow uniformity and pressure drop. [ABSTRACT FROM AUTHOR]

The effect of addition of molybdenum in Fe Cr Mn based alloy on the chromium deposition and poisoning of LSM cathodes is investigated at 800 °C by electrochemical impedance spectroscopy and microstructure analysis. The Fe Cr Mn Mo ferrite stainless steel metallic interconnect shows much less Cr deposition and poisoning on the LSM cathodes as compared with the Fe Cr Mn alloy. The addition of Mo into the alloy suppressed Cr evaporation from interconnects, decreased the degradation of cathode performance caused by Cr. According to SEM results, MoO 3 and MnMoO 4 is observed at the depositional area. The segregated MnO from LSM cathode can act as a nuclei agent, and react with vaporized Mo to form Mo-contained oxide particles, which will not inhibit the oxygen reduction reactions in the three phase boundary (TPB). As a result, suitable addition of Mo into the interconnect alloy can effectively alleviate the Cr poisoning of the LSM cathode. [ABSTRACT FROM AUTHOR]

To increase corrosion resistance of gadolinium-doped cerium oxide (GDC) electrolytes for direct carbon solid oxide fuel cells with liquid Sb anodes, GDC-based electrolytes with Fe 2 O 3 addition of 1 (GDCF-1), 2 (GDCF-2) and 3 (GDCF-3) mol.% have been prepared and evaluated chemically and electrochemically in contact with liquid Sb and Sb 2 O 3 at 750 °C for 100 h. The results show that Fe 2 O 3 addition significantly increases the resistance of the electrolytes to the chemical corrosion by liquid Sb, and GDCF-2 demonstrates the highest resistance with a corrosion affected thickness of about 60 μm, which is smaller than 1/8 of that of GDC. What's more, the affected thickness is only about 4 μm for GDCF-2 in contact with liquid Sb 2 O 3. Under a current density of 100 mA cm−2 with liquid Sb as anode, the cell voltage almost increases linearly and cell ohmic resistance decreases in the 100 h's operation. The performance promotion is resulted from the reduction of GDCF-2 thickness caused by liquid Sb/Sb 2 O 3 corrosion, but the total thickness reduction is about 200 μm, which is only 2/5 of that of GDC. • Fe 2 O 3 addition enhances GDC's resistance to hot corrosion by liquid Sb and Sb 2 O 3. • GDC with 2 mol.% Fe 2 O 3 demonstrates highest resistance to liquid Sb corrosion. • GDC with 2 mol.% Fe 2 O 3 shows a corrosion rate smaller than 1/8 of that of GDC. • Cell ohmic impedance is proved to be a feasible indicator of corrosion degree. [ABSTRACT FROM AUTHOR]

A newly developed interconnect alloy for solid oxide fuel cells, containing Fe, Cr, Mn and Mo as well as other minor elements and designated as FeCM, is investigated on its poisoning effect on (La 0.8 Sr 0.2 ) 0.95 MnO 3−δ (LSM) cathode by electrochemical impedance spectroscopy and microstructure observation. Compared with commercial SUS430 stainless steel, which is usually used as a essential interconnect in the SOFCs stacks, the FeCM alloy as the interconnect reduces the ohmic of the cell (R Ω ) and polarization resistance of the cathode (R P ) and increases the electrochemical performance of the cathode. At 850 °C the R Ω remains almost unchanged at a level slightly above 2.0 Ω cm 2 and the R P decreases from 5.76 to 1.68 Ω cm 2 within 20 h, while the cathode potential at 200 mA min −1 is virtually stabilized at below 1.0 V and the overpotential is decreased from 0.43 to 0.16 V. Based on the evidence of a narrower oxide deposition zone on the electrolyte surface near the cathode and a deposition-free cathode/electrolyte interface, this improvement is attributed to the reduced degree of volatilization of oxide scale formed on the surface of the FeCM alloy. [ABSTRACT FROM AUTHOR]