Ag Doping Modulating Cathode Acidic Sites to Enhance Chromium Resistance for Intermediate Temperature Solid Oxide Fuel Cells

doi:10.15541/jim20250105

Abstract

Abstract: Cr poisoning is an important factor restricting the practical application of solid oxide fuel cells (SOFCs) cathodes. In particular, the alkaline earth rich perovskite oxide cathodes are prone to cation segregation and impurity poisoning at high temperatures, which can significantly reduce the cathode performance. To improve the Cr resistance of the cathode, the acid site of SrCo_0.9Ta_0.1O_3-_δ (SCT) was regulated by Ag doping, and the conductivity, catalytic activity, surface morphology and composition of materials were systematically investigated. The results show that Ag doping enhances the conductivity of the material, and the doped material exhibits higher oxygen surface exchange coefficient, which is conducive to improving its cathodic catalytic activity. At 700 ℃, the polarization resistance (R_p) of Sr_0.9Ag_0.1Co_0.9Ta_0.1O_3-_δ (SACT10) cathode is 0.0176 Ω·cm², which is significantly lower than that of SCT cathode (0.0366 Ω·cm²). In addition, due to the Ag doping strategy, the average valence state of Co in SACT10 material increases, which increases the relative acidity and improves the Cr resistance. After operating in Cr-containing atmosphere for 22 h, R_p of SACT10 cathode is 0.205 Ω·cm², significantly lower than that of SCT cathode (0.964 Ω·cm²), and less inert secondary phases are observed on the surface of SACT10 cathode after testing. The above results confirm that Ag doping can effectively increase acid sites, improve activity and enhance Cr resistance. SACT10 obtained in this work is expected to be a promising medium temperature SOFCs cathode material.

Key words: solid oxide fuel cell, chromium resistance, acidic site, alkaline earth cation, surface segregation

CLC Number:

TQ174

GAO Yuan, WEI Bo, JIN Fanjun, LÜ Zhe, LING Yihan. Ag Doping Modulating Cathode Acidic Sites to Enhance Chromium Resistance for Intermediate Temperature Solid Oxide Fuel Cells[J]. Journal of Inorganic Materials, DOI: 10.15541/jim20250105.

References

[1] FU M, GAO Y, ZHANG M,et al. Vanadium-assisted surface engineering of heterostructured cathode for enhanced protonic ceramic fuel cell performance. Chemical Engineering Journal, 2025, 505: 159722.
[2] YE Z, ZOU G, WU Q,et al. Preparation and performances of tubular cone-shaped anode-supported segmented-in-series direct carbon solid oxide fuel cell. Journal of Inorganic Materials, 2024, 39(7): 819.
[3] ISHFAQ H A, KHAN M Z, SHIRKE Y M,et al. A heuristic approach to boost the performance and Cr poisoning tolerance of solid oxide fuel cell cathode by robust multi-doped ceria coating. Applied Catalysis B: Environmental, 2023, 323: 122178.
[4] GAO Y, HUANG X, WANG Z,et al. Cr deposition and poisoning on SrCo_0.9Ta_0.1O₃-_δ cathode of solid oxide fuel cells. International Journal of Hydrogen Energy, 2023, 48(6): 2341.
[5] ZHOU Y, LÜ Z, ZHANG R,et al. Mechanism of chromium poisoning on La_0.5Sr_0.5Co_0.25Fe_0.75O₃ cathode and enhancing chromium tolerance using a novel anion doping strategy. International Journal of Hydrogen Energy, 2024, 85: 114.
[6] ZHENG T, LI Z, WANG D,et al. Enhanced anti-chromium poisoning ability of high entropy La_0.2Nd_0.2Sm_0.2Sr_0.2Ba_0.2Co_0.2Fe_0.8O₃-_δ cathodes for solid oxide fuel cells. Journal of Alloys and Compounds, 2024, 982: 173753.
[7] HAO H, ZHANG Y, WANG Z,et al. Hydrogen spillover in superwetting Ni/NiMoN Mott-Schottky heterostructures for boosting ampere-level hydrogen evolution. Applied Physics Letters, 2025, 126: 113901.
[8] XIA B, ZHANG H, YAO C,et al. Enhancing ORR activity and CO₂ tolerance of Pr_0.4Sr_0.6Co_0.2Fe_0.8O₃-_δ-based SOFC cathode through synergistic doping and surface modification. Applied Surface Science, 2024, 649: 159143.
[9] BAI J, ZHOU D, NIU L,et al. Preparation of high-performance multiphase heterostructures IT-SOFC cathode materials by Pr-induced in situ assembly. Applied Catalysis B: Environment and Energy, 2024, 355: 124174.
[10] ZHANG X, LIU B, YANG Y,et al. Advances in component and operation optimization of solid oxide electrolysis cell. Chinese Chemical Letters, 2023, 34(5): 108035.
[11] LI J, HOU J, LU Y,et al. Ca-containing Ba_0.95Ca_0.05Co_0.4Fe_0.4Zr_0.1Y_0.1O₃-_δ cathode with high CO₂-poisoning tolerance for proton-conducting solid oxide fuel cells. Journal of Power Sources, 2020, 453: 227909.
[12] CHEN Z, MA B, DANG C,et al. Entropy engineering strategies for optimizing solid oxide cell air electrode performance: a review. Journal of Alloys and Compounds, 2025, 1010: 177585.
[13] ZHANG X, JIN Y, JIANG Y,et al. Enhancing chromium poisoning tolerance of La_0.8Sr_0.2Co_0.2Fe_0.8O₃-_δ cathode by Ce_0.8Gd_0.2O_1.9-_δ coating. Journal of Power Sources, 2022, 547: 231996.
[14] YUAN M, WANG Z, GAO J,et al. Turning bad into good: a medium-entropy double perovskite oxide with beneficial surface reconstruction for active and robust cathode of solid oxide fuel cells. Journal of Colloid and Interface Science, 2024, 672: 787.
[15] SHEN L, DU Z, ZHANG Y,et al. Medium-entropy perovskites Sr(Fe_αTi_βCo_γMn_ζ)O₃-_δ as promising cathodes for intermediate temperature solid oxide fuel cell. Applied Catalysis B: Environmental, 2021, 295: 120264.
[16] GAO Y, LING Y, WANG X,et al. Sr-deficient medium-entropy Sr₁-_xCo_0.5Fe_0.2Ti_0.1Ta_0.1Nb_0.1O₃-_δ cathodes with high Cr tolerance for solid oxide fuel cells. Chemical Engineering Journal, 2024, 479: 147665.
[17] GAO L, LI Q, SUN L,et al. A novel family of Nb-doped Bi_0.5Sr_0.5FeO₃-_δ perovskite as cathode material for intermediate-temperature solid oxide fuel cells. Journal of Power Sources, 2017, 371: 86.
[18] GAO Y, HUANG X, YUAN M,et al. A SrCo_0.9Ta_0.1O₃-_δ derived medium-entropy cathode with superior CO₂ poisoning tolerance for solid oxide fuel cells. Journal of Power Sources, 2022, 540: 231661.
[19] CHEN Z P, JIN F J, LI M F,et al. Double perovskite Sr₂CoFeO₅+_δ: preparation and performance as cathode material for intermediate-temperature solid oxide fuel cells. Journal of Inorganic Materials, 2024, 39(3): 337.
[20] KIM D, PARK J W, YUN B,et al. Correlation of time-dependent oxygen surface exchange kinetics with surface chemistry of La_0.6Sr_0.4Co_0.2Fe_0.8O₃-_δ Catalysts. ACS Applied Materials & Interfaces, 2019, 11(35): 31786.
[21] CHEN D, CHEN C, BAIYEE Z M,et al. Nonstoichiometric oxides as low-cost and highly-efficient oxygen reduction/evolution catalysts for low-temperature electrochemical devices. Chemical Reviews, 2015, 115(18): 9869.
[22] LIU X, ZHANG L, ZHENG Y,et al. Uncovering the Effect of Lattice Strain and Oxygen Deficiency on Electrocatalytic Activity of Perovskite Cobaltite Thin Films. Advanced Science, 2019, 6(6): 1801898.
[23] XU C, SUN W, REN R,et al. A highly active and carbon-tolerant anode decorated with in situ grown cobalt nano-catalyst for intermediate-temperature solid oxide fuel cells. Applied Catalysis B: Environmental, 2021, 282: 119553.
[24] YAO C, YANG J, ZHANG H,et al. Evaluation of A-site Ba-deficient PrBa_0.5-_xSr_0.5Co₂O₅+_δ (x = 0, 0.04 and 0.08) as cathode materials for solid oxide fuel cells. Journal of Alloys and Compounds, 2021, 883: 160759.
[25] WANG G, ZHANG Y, HAN M.Densification of Ce_0.9Gd_0.1O₂-_δ interlayer to improve the stability of La_0.6Sr_0.4Co_0.2Fe_0.8O₃-_δ/Ce_0.9Gd_0.1O₂-_δ interface and SOFC. Journal of Electroanalytical Chemistry, 2020, 857: 113591.
[26] WANG R, SUN Z, LU Y,et al. Comparison of chromium poisoning between lanthanum strontium manganite and lanthanum strontium ferrite composite cathodes in solid oxide fuel cells. Journal of Power Sources, 2020, 476: 228743.
[27] JIN F, LIU X, CHU X,et al. Effect of nonequivalent substitution of Pr³+/⁴+ with Ca²+ in PrBaCoFeO₅+_δ as cathodes for IT-SOFC. Journal of Materials Science, 2021, 56(2): 1147.
[28] YUAN M, WANG Z, GAO J,et al. Configuration entropy tailored beneficial surface segregation on double perovskite cathode with enhanced Cr-tolerance for SOFC. Ceramics International, 2024, 50(9): 15076.
[29] XIONG C, QIU P, ZHANG W,et al. Influence of practical operating temperature on the Cr poisoning for LSCF-GDC cathode. Ceramics International, 2022, 48(22): 33999.
[30] GAO M, KONYSHEVA E Y, YANG J.Tailoring kinetics of Cr-chemisorption over La_0.6Sr_0.4Fe_0.8Co_0.2O₃ cathode material through its porosity variation.International Journal of Hydrogen Energy, 2022, 47(97): 41336.
[31] PAN Y, XU X, ZHONG Y,et al. Direct evidence of boosted oxygen evolution over perovskite by enhanced lattice oxygen participation. Nature Communications, 2020, 11: 2002.
[32] ZHAO Y, DONGFANG N, HUANG C,et al. Operando monitoring of the functional role of tetrahedral cobalt centers for the oxygen evolution reaction. Nature Communications, 2025, 16(1): 580.
[33] JEONG N C, LEE J S, TAE E L,et al. Acidity scale for metal oxides and Sanderson's electronegativities of lanthanide elements. Angewandte Chemie International Edition, 2008, 47(52): 10128.
[34] NICOLLET C, TOPARLI C, HARRINGTON G F,et al. Acidity of surface-infiltrated binary oxides as a sensitive descriptor of oxygen exchange kinetics in mixed conducting oxides. Nature Catalysis, 2020, 3(11): 913.
[35] XIAOKAITI P, YU T, YOSHIDA A,et al. Effects of cobalt and iron proportions in Pr_0.4Sr_0.6Co_0.9-_xFe_xNb_0.1O₃-_δ electrode material for symmetric solid oxide fuel cells. Journal of Alloys and Compounds, 2020, 831: 154738.
[36] ZHANG W, ZHANG L, GUAN K,et al. Effective promotion of oxygen reduction activity by rare earth doping in simple perovskite cathodes for intermediate-temperature solid oxide fuel cells. Journal of Power Sources, 2020, 446: 227360.