Application of Sr₂FeMoO_6−δ-based medium entropy oxide as an anode internal reforming catalyst in solid oxide fuel cells fueled by low-concentration coal mine methane

Abstract

Low-concentration coal mine methane (LC-CMM), which is predominantly composed of methane, serves as a clean and low-carbon energy resource with significant potential for utilization. Utilizing LC-CMM as fuel for solid oxide fuel cells (SOFCs) represents an efficient and promising strategy for its effective utilization. However, direct application in Ni-based anodes induces carbon deposition, which severely degrades cell performance. Herein, a medium-entropy oxide Sr₂FeNi_0.1Cr_0.3Mn_0.3Mo_0.3O_6−δ (SFNCMM) was developed as an anode internal reforming catalyst. Following reduction treatment, FeNi₃ nano-alloy particles precipitate on the surface of the material, thereby significantly enhancing its catalytic activity for LC-CMM reforming process. The catalyst achieved a methane conversion rate of 53.3%, demonstrating excellent catalytic performance. Electrochemical evaluations revealed that SFNCMM-Gd_0.1Ce_0.9O_2−δ (GDC) with a weight ratio of 7:3 exhibited superior electrochemical performance when employed as the anodic catalytic layer. With H₂ and LC-CMM as fuels, the single cell achieved maximum power densities of 1467.32 and 1116.97 mW·cm⁻² at 800°C, respectively, with corresponding polarization impedances of 0.17 and 1.35 Ω·cm². Furthermore, the single cell maintained stable operation for over 100 h under LC-CMM fueling without significant carbon deposition, confirming its robust resistance to carbon formation. These results underscore the potential of medium-entropy oxides as highly effective catalytic layers for mitigating carbon deposition in SOFCs.

Keywords

solid oxide fuel cell / medium entropy oxide / low-concentration coal mine methane / anode internal reforming catalyst / electrochemical performance

References

[1] Shao ZP, Haile SM. A high-performance cathode for the next generation of solid-oxide fuel cells. Nature, 2004, 431(7005170

[2] Tao SW, Irvine JTS. A redox-stable efficient anode for solid-oxide fuel cells. Nat. Mater., 2003, 2(5320

[3] Z.X. Liu, Y.Y. Gu, and L. Bi, Applications of electrospun nanofibers in solid oxide fuel cells - A review, J. Alloy. Compd., 937(2023), No. 168288.

[4] Yang X, Du ZH, Zhang Q, et al.. Effects of operating conditions on the performance degradation and anode microstructure evolution of anode-supported solid oxide fuel cells. Int. J. Miner. Metall. Mater., 2023, 30(61181

[5] X. Han, Y.H. Ling, Y. Yang, et al., Utilizing high entropy effects for developing chromium-tolerance cobalt-free cathode for solid oxide fuel cells, Adv. Funct. Mater, 33(2023), No. 43, art No. 2304728.

[6] Ye ZB, Zou GC, Wu QW, Yan XM, Zhou MY, Liu J. Preparation and performances of tubular cone-shaped anode-supported segmented-in-series direct carbon solid oxide fuel cell. J. Inorg. Mater., 2024, 39(7819

[7] Feng XB, Jiang L, Li DY, et al.. Progress and key challenges in catalytic combustion of lean methane. J. Energy Chem., 2022, 75: 173

[8] K.W. Wei, H. Liu, P. Qiu, and Z.G. Guo, Efficient upgrading of low-concentration coal mine methane with carbon molecular sieves: Performance evaluation and process optimization, Chem. Eng. J., 512(2025), art No. 162352.

[9] X.X. Wang, K.W. Wei, S.L. Yan, et al., Efficient and stable conversion of oxygen-bearing low-concentration coal mine methane by the electrochemical catalysis of SOFC anode: From pollutant to clean energy, Appl. Catal. B, 268(2020), art No. 118413.

[10] Y. Yang, T. Li, P.Z. Feng, et al., Highly efficient conversion of oxygen-bearing low concentration coal-bed methane into power via solid oxide fuel cell integrated with an activated catalyst-modified anode microchannel, Appl. Energy, 328(2022), art No. 120134.

[11] Liu SX, Liu ZJ, Zhang SX, Wu H. Lattice boltzmann simulation study of anode degradation in solid oxide fuel cells during the initial aging process. Int. J. Miner. Metall. Mater., 2024, 31(2405

[12] Han S, Wei T, Wang SJ, et al.. Recent progresses in the development of tubular segmented-in-series solid oxide fuel cells: Experimental and numerical study. Int. J. Miner. Metall. Mater., 2024, 31(3427

[13] T. Wei, P. Qiu, J. Yang, et al., High-performance direct carbon dioxide-methane solid oxide fuel cell with a structure-engineered double-layer anode, J. Power Sources, 484(2021), art No. 229199.

[14] Y.W. Wang, X.Y. Zhang, M.Y. Yang, S.L. Fu, and Q.J. Zhou, A-site high entropy and B-site medium entropy double perovskite structure cathode material for solid oxide fuel cells, J. Alloy. Compd., 1022(2025), art No. 180002.

[15] Z.P. Li, Y.F. Ge, Y.H. Xiao, et al., Fabrication and performance investigation of high entropy perovskite (Sr_0.2Ba_0.2Bi_0.2La_0.2Pr_0.2)FeO₃ IT-SOFC cathode material, J. Alloy. Compd., 989(2024), art No. 174357.

[16] Z.Y. Jiang, B.J.M. Sarruf, A. El-kharouf, W.F. Zhan, Z.X. Liang, and R. Steinberger-Wilckens, Evaluation of electrochemical performance and carbon deposition behaviour of Sn, Ag, Cu, Fe-doped Ni/ScCeSZ anode solid oxide fuel cells operated with simulated biogas, Chem. Eng. J., 505(2025), art No. 159392.

[17] Q. Li, X. Wang, L. Jia, B. Chi, J. Pu, and J. Li, High performance and carbon-deposition resistance metal-supported solid oxide fuel cell with a nickel-manganese spinel modified anode, Mater. Today Energy, 17(2020), No. 100473.

[18] D. Go, T. Kim, H.Y. Li, et al., PEALD Ru-decorated Ni-SDC cermet anode for utilizing methane fuel in low-temperature SOFCs, Surf. Interfaces, 44(2024), art No. 103657.

[19] N. Wongsawatgul, H. Takayanagi, H. Nishiyama, S. Chaianansutcharit, and K. Sato, Specific adsorptive properties and anodic polarization characteristics for hydrogen and methane in the Ni_1−xCo_x solid-solution alloy combined with yttria-stabilized zirconia, Mater. Lett., 366(2024), art No. 136561.

[20] Z.Y. Han, H. Dong, H.W. Wang, Y.R. Yang, H. Yu, and Z.B. Yang, Temperature-dependent chemical incompatibility between NiO-YSZ anode and alkaline earth metal oxides: implications for surface decoration of SOFC anode, J. Alloy. Compd., 968(2023), art No. 172150.

[21] M. Soleimanpour and M. Ebrahimi, Energy and exergy analysis of dry and steam external reformers for a power cycle based on biogas-fueled solid oxide fuel cell, Energy, 305(2024), art No. 132382.

[22] M. Höber, B. Königshofer, H. Schröttner, et al., Experimental identification of the impact of direct internal and external methane reforming on SOFC by detailed online monitoring and supporting measurements, J. Power Sources, 581(2023), art No. 233449.

[23] Laosiripojana N, Assabumrungrat S. Catalytic steam reforming of ethanol over high surface area CeO₂: The role of CeO₂ as an internal pre-reforming catalyst. Appl. Catal. B, 2006, 66(129

[24] Z.W. Lyu, Y.D. Liu, A. Sciazko, et al., Co-generation of electricity and chemicals from methane using direct internal reforming solid oxide fuel cells, Adv. Energy Mater., 15(2025), No.10, art No. 2403869.

[25] Zhan ZL, Barnett SA. An octane-fueled solid oxide fuel cell. Science, 2005, 308(5723844

[26] Lay E, Metcalfe C, Kesler O. The influence of incorporating MgO into Ni-based cermets by plasma spraying on anode microstructural and chemical stability in dry methane. J. Power Sources, 2012, 218: 237

[27] Qiu P, Yang X, Sun SC, Jia LC, Li J, Chen FL. Enhanced electrochemical performance and durability for direct CH₄–CO₂ solid oxide fuel cells with an on-cell reforming layer. Int. J. Hydrogen Energy, 2021, 46(4422974

[28] de Lira Lima DC, Lemos IP, Gomes RS, et al.. Study of LaNi_1−xCo_xO₃ perovskites-type oxides either pure or mixed with SiO₂ as catalytic precursors applied in CH₄ dry-reforming. Catal. Lett., 2023, 153(72137

[29] Chen B, Xu HR, Sun Q, et al.. Syngas/power cogeneration from proton conducting solid oxide fuel cells assisted by dry methane reforming: a thermal-electrochemical modelling study. Energy Convers. Manage., 2018, 167: 37

[30] Lv XQ, Chen HL, Zhou W, Cheng FQ, Li SD, Shao ZP. Direct-methane solid oxide fuel cells with an in situ formed Ni–Fe alloy composite catalyst layer over Ni-YSZ anodes. Renewable Energy, 2020, 150: 334

[31] A. Bhaskaran and S. Roy, Exploring dry reforming of CH₄ to syngas using high-entropy materials: A novel emerging approach, ChemCatChem, 17(2025), No.1, art. No. e202401297.

[32] T.Y. Zhao, Q.W. Shen, M. Andersson, S.A. Li, and J.L. Yuan, Surface of high-entropy perovskite catalyst La(CoCuFeAlCe)_0.2O₃ (100): Experimental study of methanol steam reforming for hydrogen production and DFT mechanism research, Appl. Surf. Sci., 684(2025), art No. 161917.

[33] Zheng Y, Ran R, Shao ZP. Cr doping effect in B-site of La_0.75Sr_0.25MnO₃ on its phase stability and performance as an SOFC anode. Rare Met., 2009, 28(4361

[34] Jarvis A, Berry FJ, Marco JF, Slater PR. Introduction of sulfate to stabilize the n = 3 ruddlesden-popper system Sr₄Fe₃O_10−δ as a potential SOFC cathode. ECS Trans., 2019, 91(11467

[35] T. Ghorbani-Moghadam, A. Kompany, and M. Golmohammad, The comparative study of doping Cu and Fe on the cathodic properties of La_0.7Sr_1.3CoO₄ layered perovskite compound: To be used in IT-SOFC, J. Alloy. Compd., 926(2022), art No. 166928.

[36] F.J. Jin, X.W. Liu, B.B. Niu, et al., A new highly active and CO₂-stable heterostructure cathode material for solid oxide fuel cells developed from bismuth ion-modified cation-deficient Nd_0.9BaCo₂O_5+δAppl. Catal. B, 358(2024), art No. 124410.

[37] F.J. Jin, X.W. Liu, Y.F. Tian, and Y.H. Ling, Enhancing oxygen reduction activity and CO₂ tolerance by a bismuth doping strategy for solid oxide fuel cell cathodes, Adv. Funct. Mater., 34(2024), No.29, art No. 2400519.

[38] Subotić V, Schluckner C, Mathe J, Rechberger J, Schroettner H, Hochenauer C. Anode regeneration following carbon depositions in an industrial-sized anode supported solid oxide fuel cell operating on synthetic diesel reformate. J. Power Sources, 2015, 295: 55

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