High-Entropy Alloys FeCoNiCuX (X = Al, Mo)-Ce_0.8Sm_0.2O₂ as High-Performance Solid Oxide Fuel Cell Anodes

Abstract

High-entropy alloys (HEAs) have received a lot of attention in electrocatalysis due to their potent synergistic effects of uniformly mixing many elements. In this study, HEAs FeCoNiCuX (X = Al, Mo)-Ce0.8Sm0.2O2 (SDC) are considered as a prospective intermediate temperature solid oxide fuel cell (SOFC) anode. FeCoNiCuX-SDC as a SOFC anode shows comparable high conductivity with a Ni-based anode and exhibits outstanding catalytic capability for H2, CH4, and CO2. The LSGM electrolyte-supported single cell with FeCoNiCuAl-SDC as anode shows maximum power densities of 779 and 526 mW cm–2 with H2 and CH4 as fuel gases and testing at 850 °C, respectively. The distribution of relaxation time analysis shows that the prime speed-limiting steps for the FeCoNiCuX-SDC anode are the adsorption/dissociation of fuel gas. X-ray photoelectron spectroscopy results showed that FeCoNiCuX HEAs with the main constituents in different valence states created more active sites, which provided a synergistic effect for H2, CH4, and CO2 catalysis.

Toward High CO Selectivity and Oxidation Resistance Solid Oxide Electrolysis Cell with High-Entropy Alloy

“…X-ray diffraction (XRD) analysis indicated that the as-synthesized FCNCM exhibited a single-phase metal structure, with no detectable presence of other oxides (Figures 1b and S1). The diffraction peaks at approximately 44 and 51°c orresponded to the (111) and (200) crystal planes of the facecentered cubic (FCC) structure, 31 with lattice distances of 2.2 and 1.9 Å, respectively. When compared to diffraction patterns of pure metals and binary alloy (Figures 1b and S2), it was evident that the diffraction peaks of FCNCM closely resembled those of Co 0.5 Ni 0.5 (PDF#04−004−8490), with noticeable shifts relative to the simple metal phases.…”

“…Furthermore, control of lattice distortion in high-entropy alloys offers a unique approach for enhancing their oxidation-resistant capability . Extensive research has confirmed that properly designed high-entropy alloys can achieve high electrocatalytic and thermocatalytic activity such as oxygen evolution reaction, ammonia decomposition, and CO 2 hydrogenation. − Some thoughtfully designed HEAs show excellent resistance to carbon deposition in solid oxide fuel cells (SOFCs), , but the performance and mechanism of HEAs in SOECs have not been studied yet.…”

Smart Dual‐Exsolved Self‐Assembled Anode Enables Efficient and Robust Methane‐Fueled Solid Oxide Fuel Cells

“…Among them, the LF‐R p is dramatically reduced, indicative of the significantly enhanced CH 4 absorption/dissociation kinetics after Ru dual‐exsolution. [ 33 ]…”

“… I−V and I−P curves of the CH 4 fueled single cells using a) SFM/GDC anode and b) Ru@Ru‐SFM/Ru‐GDC anode, c) EIS curves and d) DRT analysis, e) cell potential as function of elapsed time for the Ru@Ru‐SFM/Ru‐GDC single cell, f) comparison of the peak power densities of CH 4 fueled single cells (Sr 2 Fe 1.5 Mo 0.5 O 6–δ (SFM), [ 9a ] Sr 2 ZnMoO (R‐SZMO), [ 25 ] Co@Sr 2 Fe 1.3 Co 0.2 Mo 0.5 O 6‐δ (Co@SFCM), [ 26 ] CoNiMo/Sr 2 FeMoO 6–δ (CNM/SFM), [ 27 ] CoFe@La 0.5 Ba 0.5 Mn 0.8 Fe 0.1 Co 0.1 O 3‐δ (CoFe@LBMFC), [ 28 ] Pr 6 O 11 ‐PrBaMn 2 O 5+δ (Pr‐PBMO), [ 29 ] Ni@La 0.4 Sr 0.4 Ti 0.85 Ru 0.07 Ni 0.08 O 3−δ (Ni@L0.4STRN), [ 30 ] Ni@(La 0.2 Sr 0.8 ) 0.925 Ti 0.55 Mn 0.35 Ni 0.1 O 3‐δ (Ni@LSTMN), [ 31 ] NiFe@La 0.6 Ce 0.1 Sr 0.3 Fe 0.9 Ni 0.1 O 3‐δ (NiFe@CLSFNi), [ 32 ] FeCoNiCuAl‐Sm 0.2 Ce 0.8 O 2 (FeCoNiCuAl‐SDC) [ 33 ] ). …”

“…As depicted in Figure 6e, the cell voltage remains consistently stable at ≈0.59 V for 200 h. Of note, the PPD and durability of the CH 4 fueled single cell using the Ru@Ru-SFM/Ru-GDC anode favorably rival most of previously reported perovskite anodes, as illustrated in Figure 6f and Table S5 (Supporting Information). No Raman carbon peaks, including the Dband at 1357 cm −1 and G-band at 1585 cm −1 , are detected on the Ru@Ru-SFM/Ru-GDC anode after the extensive long-term analysis, e) cell potential as function of elapsed time for the Ru@Ru-SFM/Ru-GDC single cell, f) comparison of the peak power densities of CH 4 fueled single cells (Sr 2 Fe 1.5 Mo 0.5 O 6-𝛿 (SFM), [9a] Sr 2 ZnMoO (R-SZMO), [25] Co@Sr 2 Fe 1.3 Co 0.2 Mo 0.5 O 6-𝛿 (Co@SFCM), [26] CoNiMo/Sr 2 FeMoO 6-𝛿 (CNM/SFM), [27] CoFe@La 0.5 Ba 0.5 Mn 0.8 Fe 0.1 Co 0.1 O 3-𝛿 (CoFe@LBMFC), [28] Pr 6 O 11 -PrBaMn 2 O 5+𝛿 (Pr-PBMO), [29] Ni@La 0.4 Sr 0.4 Ti 0.85 Ru 0.07 Ni 0.08 O 3−𝛿 (Ni@L0.4STRN), [30] Ni@(La 0.2 Sr 0.8 ) 0.925 Ti 0.55 Mn 0.35 Ni 0.1 O 3-𝛿 (Ni@LSTMN), [31] NiFe@La 0.6 Ce 0.1 Sr 0.3 Fe 0.9 Ni 0.1 O 3-𝛿 (NiFe@CLSFNi), [32] FeCoNiCuAl-Sm 0.2 Ce 0.8 O 2 (FeCoNiCuAl-SDC) [33] ). stability test (Figure 7a), demonstrating the exceptional resistance of the Ru@Ru-SFM/Ru-GDC anode to carbon deposition during CH 4 exposure.…”