Breaking the activity-stability trade-off of iridium-based catalysts for proton exchange membrane water electrolyzers

doi:10.1016/S1872-2067(26)64962-5

Abstract

Abstract:

Achieving both high activity and stability remains a key bottleneck for Ir-based catalysts in the acidic oxygen evolution reaction (OER) for proton exchange membrane water electrolyzers (PEMWEs). Herein, we present a cobalt-doped iridium oxide catalyst coated on tungsten substrate (Co-IrO_x/W) fabricated via a synergistic magnetron sputtering and unipolar pulse electrodeposition strategy. The optimized catalyst demonstrates exceptional acidic OER activity with an ultralow overpotential of 209 mV at 10 mA cm^-2 in 0.5 mol L^-1 H₂SO₄, and a Ir loading only of 0.262 mg cm^-2 in PEMWEs to achieve over 1000 h of stable operation at 1 A cm^-2 with a degradation rate only of 6.8 µV h^-1. Integrated characterization reveals enhanced catalytic capacity of Co-IrO_x/W in activation energy, deprotonation, and charge transfer stemmed from Co doping induced Ir d-band upward, strengthening oxygen-intermediate adsorption and accelerates OER kinetics. Moreover, the W substrate creates a W-O-Ir interfacial coordination that dynamically suppresses over-oxidation of Ir sites via electronic redistribution, thereby enhancing the stability of iridium oxide catalyst. This work offers design insights for OER catalysts to simultaneously overcome activity-stability limitations through rational electronic-structure engineering and support interactions dual design principles, opening avenues for industrial hydrogen production.

Key words: Proton exchange membrane water electrolyzers, Oxygen evolution reaction, Ir-based catalysts, Doping, Support

Kaiyang Zhang, Huihui Li, Shuhao Wang, Rui Yao, Jinping Li, Chuan Zhao, Guang Liu. Breaking the activity-stability trade-off of iridium-based catalysts for proton exchange membrane water electrolyzers[J]. Chinese Journal of Catalysis, 2026, 85: 193-203.

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URL: https://www.cjcatal.com/EN/10.1016/S1872-2067(26)64962-5

https://www.cjcatal.com/EN/Y2026/V85/I6/193

Figures/Tables 6

Fig. 1. (a) Schematic illustration of the synthesis process of Co-IrOx/W. SEM image (b), TEM image (c), HR-TEM image (d), SAED image (e), HAADF-STEM image (f), and corresponding EDS mappings (g) of Co-IrOx/W.

Fig. 2. Raman spectra (a) and High-resolution XPS spectra of Ir 4f (b) of Co-IrOx/W, Co-IrOx, and IrOx/W. (c) Analysis of Ir chemical states in Co-IrO?/W, Co-IrO?, and IrO?/W via Ir 4f XPS spectra. (d) High-resolution XPS spectra of W 4f of Co-IrOx/W and IrOx/W. Ir L3-edge XANES regions (e) and Fourier-transforms of k3-weight Ir L3-edge EXAFS spectra (f) of Co-IrOx/W, Ir foil, and IrO2. W L3-edge XANES regions (g) and Fourier-transforms of k3-weight W L3-edge EXAFS spectra (h) of Co-IrOx/W, W foil, and WO3. (i) Wavelet transforms for the k3-weighted Ir L3-edge and W L3-edge EXAFS signals of Co-IrOx/W.

Fig. 3. LSV curves (a), Overpotential at 10 mA cm-2 and mass activity 1.45 V (b), and Tafel slopes (c) of Co-IrOx/W, Co-IrOx, IrOx/W, and IrO2. (d) TOF values at 250 and 300 mV overpotential of Co-IrOx/W, Co-IrOx, and IrOx/W. (e) CP measurement for Co-IrOx/W and Co-IrOx at different current densities.

Fig. 4. (a) pH dependence of Co-IrOx/W and IrOx/W. (b) Polarization curves of Co-IrOx/W and IrOx/W in the presence or absence of TMAOH in H2SO4 electrolytes. (c) AEM pathways in acidic OER process for Co-IrOx. (d) The comparison of integrated -COHP values for Ir-O hybridization for Co-IrOx and IrOx. (e) Gibbs free-energy and (f) computed DOS diagrams of Co-IrOx and IrOx. (g) Arrhenius plots, (h) Phase peak angles and (i) Linear stored charge versus potential relationships for Co-IrOx/W and IrOx/W.

Fig. 5. (a) CP measurement for Co-IrOx/W and Co-IrOx at 400 mA cm-2, the inset displays the calculated S-number from produced O2/dissolved Ir. (b) Variation of Ir dissolution with time at 400 mA cm-2 for Co-IrOx/W and Co-IrOx. High-resolution XPS spectra of (c) Ir 4f and (d) Co 2p (d) were obtained for Co-IrOx/W and Co-IrOx after electrochemical measurement. (e) High-resolution XPS spectra of O 1s were obtained for Co-IrOx/W before and after electrochemical measurement.

Fig. 6. (a) Schematic diagram of PEMWEs. (b) Polarization curves of PEMWEs using Co-IrOx/W||Pt/C, IrOx/W||Pt/C, and IrO2||Pt/C, inset displays a digital photograph of the PEMWEs device. (c) Nyquist plots of Co-IrOx/W||Pt/C and IrO2||Pt/C at 1.7 V. (d) Breakdown of ohmic, transport, and kinetic losses for Co-IrOx/W||Pt/C. (e) The comparison of ohmic, transport, and kinetic losses for PEMWEs using Co-IrOx/W||Pt/C and IrO2||Pt/C. (f) Chronopotentiometry curve of PEMWEs using Co-IrOx/W||Pt/C and Co-IrOx||Pt/C at 1 A cm-2 current density. (g) Comparison of Co-IrO?/W with reported catalysts in terms of Ir loading and stability.

References

[1]	B. Pang, S. Feng, Y. Xu, H. Chen, J. Li, Y. Yuan, X. Zou, X. Tian, Z. Kang, Adv. Funct. Mater., 2024, 34, 2411062.
[2]	H. G. Han, J. W. Choi, M. Son, K. C. Kim, eScience, 2024, 4, 100204.
[3]	L. Zhou, Y. Shao, F. Yin, J. Li, F. Kang, R. Lv, Nat. Commun., 2023, 14, 7644.
[4]	P. Sun Z,. Qiao X,. Dong R,. Jiang Z.-T., Hu J,. Yun D. Cao, J. Am. Chem. Soc., 2024, 146, 15515-15524.
[5]	J. Xu H,. Jin T,. Lu J,. Li Y,. Liu K,. Davey Y,. Zheng S.-Z. Qiao, Sci. Adv., 2023, 9, eadh1718.
[6]	J. R. Kuang, B. L. Deng Z. Q., Jiang Y. J., Wang Z. J. Jiang, Adv. Mater., 2024, 36, 2306934.
[7]	S. Chen, H. Huang, P. Jiang, K. Yang, J. Diao, S. Gong, S. Liu, M. Huang, H. Wang, Q. Chen, ACS Catal., 2020, 10, 1152-1160.
[8]	Y. Wang, S. Hao, X. Liu, Q. Wang, Z. Su, L. Lei, X. Zhang, ACS Appl. Mater. Interfaces, 2020, 12, 37006-37012.
[9]	K. Hua X,. Li Z,. Rui X,. Duan Y,. Wu D,. Yang J,. Li J. Liu, ACS Catal., 2024, 14, 3712-3724.
[10]	S. Ge R,. Xie B,. Huang Z,. Zhang H,. Liu X,. Kang S,. Hu S,. Li Y,. Luo Q,. Yu J,. Wang G,. Chai L,. Guan H.-M., Cheng B. Liu, Energy Environ. Sci., 2023, 16, 3734-3742.
[11]	J. Kim J,. Guo N,. Shan J,. Yoo J,. Noh M,. Jung P,. Zapol B. S., Mun R,. Klie P. P., Lopes N. M., Markovic D. Y. Chung, J. Am. Chem. Soc., 2025, 147, 16340-16349.
[12]	X. Han T,. Mou A,. Islam S,. Kang Q,. Chang Z,. Xie X,. Zhao K,. Sasaki J. A., Rodriguez P,. Liu J. G. Chen, J. Am. Chem. Soc., 2024, 146, 16499-16510.
[13]	C. Yang, W. Ling, Y. Zhu, Y. Yang, S. Dong, C. Wu, Z. Wang, S. Yang, J. Li, G. Wang, Y. Huang, B. Yang, Q. Cheng, Z. Liu, H. Yang, Appl. Catal. B, 2024, 358, 124462.
[14]	J.-W. Zhao, K. Yue, H. Zhang, S.-Y. Wei, J. Zhu, D. Wang, J. Chen, V. Y. Fominski, G.-R. Li, Nat. Commun., 2024, 15, 2928.
[15]	C. Wang, P. Zhai, M. Xia, Y. Wu, B. Zhang, Z. Li, L. Ran, J. Gao, X. Zhang, Z. Fan, L. Sun, J. Hou, Angew. Chem. Int. Ed., 2021, 60, 27126-27134.
[16]	T. Tang, J. Zessin, F. Talnack, K. Haase, K. Ortstein, B. Li, M. Löffler, B. Rellinghaus, M. Hambsch, S. C. B. Mannsfeld, ACS Appl. Mater. Interfaces, 2021, 13, 43051-43062.
[17]	W. Zhao, Y. Wang, M. Han, J. Xu, L. Han, K. C. Tam, Nano Energy, 2022, 98, 107291.
[18]	Y. Sim T. G., Yun K. H., Park D,. Kim H. B., Bae S.-Y. Chung, Nat. Commun., 2025, 16, 4152.
[19]	H. Ding, C. Su, J. Wu, H. Lv, Y. Tan, X. Tai, W. Wang, T. Zhou, Y. Lin, W. Chu, X. Wu, Y. Xie, C. Wu, J. Am. Chem. Soc., 2024, 146, 7858-7867.
[20]	Z. Guan, J. Li, S. Li, K. Wang, L. Lei, Y. Wang, L. Zhuang, Z. Xu, Small Methods, 2024, 8, 2301419.
[21]	L.-Y. Chueh, C.-H. Kuo, R.-H. Yang, D.-H. Tsai, M.-H. Tsai, C.-C. Yang, H.-Y. Chen, C.-H. Wang, Y.-T. Pan, Chem. Eng. J., 2023, 464, 142613.
[22]	X. Liu Y,. Wang J,. Liang S,. Li S,. Zhang D,. Su Z,. Cai Y,. Huang L,. Elbaz Q. Li, J. Am. Chem. Soc., 2024, 146, 2033-2042.
[23]	P. J. Kelly, R. D. Arnell, Vacuum, 2000, 56, 159-172.
[24]	R. Yao K,. Sun K,. Zhang Y,. Wu Y,. Du Q,. Zhao G,. Liu C,. Chen Y,. Sun J. Li, Nat. Commun., 2024, 15, 2218.
[25]	C. W. Lee, C., Cazorla S,. Zhou D,. Zhang H,. Xu W,. Zhong M,. Zhang D,. Chu Z,. Han R. Amal, Adv. Energy Mater., 2025, 15, 2402786.
[26]	R. S. Chen, Y. S. Huang, Y. M. Liang, D. S. Tsai, K. K. Tiong, J. Alloys Compd., 2004, 383, 273-276.
[27]	A. V. Korotcov, Y.-S. Huang, K.-K. Tiong, D.-S. Tsai, J. Raman Spectrosc., 2007, 38, 737-749.
[28]	Y. Wang, X. Lei, B. Zhang, B. Bai, P. Das, T. Azam, J. Xiao, Z.-S. Wu, Angew. Chem. Int. Ed., 2024, 63, e202316903.
[29]	Y. Sun M,. Xiao F,. Liu J,. Gan S,. Gao J. Liu, Adv. Mater., 2024, 36, 2414579.
[30]	S. J. Freakley, J. Ruiz-Esquius D. J. Morgan, Surf. Interface Anal., 2017, 49, 794-799.
[31]	V. Pfeifer, T. E. Jones, J. J. Velasco Vélez, C. Massué, R. Arrigo, D. Teschner, F. Girgsdies, M. Scherzer, M. T. Greiner, J. Allan, M. Hashagen, G. Weinberg, S. Piccinin, M. Hävecker, A. Knop-Gericke, R. Schlögl, Surf. Interface Anal., 2016, 48, 261-273.
[32]	Z. Lu H,. Yang G,. Qi Q,. Liu L,. Feng H,. Zhang J,. Luo X. Liu, Small, 2024, 20, 2308841.
[33]	Y. Guo F,. Liu L,. Feng X,. Wang X,. Zhang J. Liang, Chem. Eng. J., 2022, 429, 132150.
[34]	M. Chen, D. Liu, B. Zi, Y. Chen, D. Liu, X. Du, F. Li, P. Zhou, Y. Ke, J. Li, K. H. Lo, C. T. Kwok, W. F. Ip, S. Chen, S. Wang, Q. Liu, H. Pan, J. Energy Chem., 2022, 65, 405-414.
[35]	G. Qian, J. Chen, W. Jiang, T. Yu, K. Tan, S. Yin, Carbon Energy, 2023, 5, e368.
[36]	J. Bhattarai, E. Akiyama, A. Kawashima, K. Asami, K. Hashimoto, Corros. Sci., 1995, 37, 2071-2086.
[37]	H. Chen, L. Song, S. Ouyang, J. Wang, J. Lv, J. Ye, Adv. Sci., 2019, 6, 1900465.
[38]	R. D. L,. Smith B,. Sporinova R. D., Fagan S,. Trudel C. P. Berlinguette, Chem. Mater., 2014, 26, 1654-1659.
[39]	F. Huang, Q. Wang, W. Wang, J. Wu, S. Wang, Y. Zou, P. Bi, L. Wen, Y. Jin, Coatings, 2021, 11, 1202.
[40]	H. Gao Z,. Xiao S,. Du T,. Liu Y.-C., Huang J,. Shi Y,. Zhu G,. Huang B,. Zhou Y,. He C.-L., Dong Y,. Li R,. Chen S. Wang, Angew. Chem. Int. Ed., 2023, 62, e202313954.
[41]	Z. Chen, W. Gong, J. Wang, S. Hou, G. Yang, C. Zhu, X. Fan, Y. Li, R. Gao, Y. Cui, Nat. Commun., 2023, 14, 5363.
[42]	Z. Shi Y,. Wang J,. Li X,. Wang Y,. Wang Y,. Li W,. Xu Z,. Jiang C,. Liu W,. Xing J. Ge, Joule, 2021, 5, 2164-2176.
[43]	S. W. Lee, C. Baik, D.-H. Kim, C. Pak, J. Power Sources, 2021, 493, 229689.
[44]	D. W. Fuerstenau, M. C. Williams K. S., Narayanan J. L., Diao R. H. Urbina, Energy Fuels, 1988, 2, 237-241.
[45]	T. Zhu S,. Liu B,. Huang Q,. Shao M,. Wang F,. Li X,. Tan Y,. Pi S.-C., Weng B,. Huang Z,. Hu J,. Wu Y,. Qian X. Huang, Energy Environ. Sci., 2021, 14, 3194-3202.
[46]	L. Zhang, H. Jang, H. Liu, M. G. Kim, D. Yang, S. Liu, X. Liu, J. Cho, Angew. Chem. Int. Ed., 2021, 60, 18821-18829.
[47]	Y. Chen, D. Liu, Q. Zhao, X. Long, J. Wang, J. Zhang, X.-Z. Fu, J.-L. Luo, Chem. Eng. J., 2023, 475, 146255.
[48]	L. P. Yao, F. R. Zhang S,. Yang H,. Zhang Y. Z., Li C. L., Yang H,. Yang Q. Q. Cheng, Adv. Mater., 2024, 36, 2314049.
[49]	M. Sun H,. Huang X,. Niu S,. Gong Z,. Li J,. Fang X,. Liu Y,. Chen H,. Duan Z,. Zhuang S,. Nagao Y,. Aoki L,. Zhang Z. Niu, ACS Catal., 2024, 14, 15764-15776.
[50]	X. Wang, H. Zhong, S. Xi, W. S. V. Lee, J. Xue, Adv. Mater., 2022, 34, 2107956.
[51]	X. Tan M,. Zhang D,. Chen W,. Li W,. Gou Y,. Qu Y. Ma, Small, 2023, 19, 2303249.
[52]	Q. Dang, H. Lin, Z. Fan, L. Ma, Q. Shao, Y. Ji, F. Zheng, S. Geng, S.-Z. Yang, N. Kong, W. Zhu, Y. Li, F. Liao, X. Huang, M. Shao, Nat. Commun., 2021, 12, 6007.
[53]	L. Wang, R. Du, Z. Zhao, M. Na, X. Li, X. Zhao, X. Wang, Y. A. Wu, S. Jana, Y. Zou, H. Chen, X. Zou, Angew. Chem. Int. Ed., 2025, 64, e202501744.
[54]	M. Qu, H. Liu, S. Feng, X Su, J. Xu, H. Duan, R. Liu, Y. Qin, W. Yan, S. Zhu, R. Wu, H. Li, S. Yu, Nat. Commun., 2025, 16, 9261.
[55]	L. Li G. W., Zhang J. W., Xu H. J., He B,. Wang Z. M., Yang S. C. Yang, Adv. Funct. Mater., 2023, 33, 2213304.
[56]	W. Li J,. Lv X,. Chen B,. Wang L. Wang, J. Am. Chem. Soc., 2025, 147, 29505-29516.
[57]	L. Li G,. Zhang C,. Zhou F,. Lv Y,. Tan Y,. Han H,. Luo D,. Wang Y,. Liu C,. Shang L,. Zeng Q,. Huang R,. Zeng N,. Ye M,. Luo S. Guo, Nat. Commun., 2024, 15, 4974.
[58]	Y. Duan, N. Dubouis, J. Huang, D. A. Dalla Corte, V. Pimenta, Z. J. Xu, A. Grimaud, ACS catal., 2020, 10, 4160-4170.
[59]	Z. Xie X,. Liang Z,. Kang Y,. Zou X,. Wang Y. A., Wu G,. King Q,. Liu Y,. Huang X,. Zhao H,. Chen X. Zou, CCS Chem., 2025, 7, 216-228.
[60]	Z. Shi J,. Li J,. Jiang Y,. Wang X,. Wang Y,. Li L,. Yang Y,. Chu J,. Bai J,. Yang J,. Ni Y,. Wang L,. Zhang Z,. Jiang C,. Liu J,. Ge W. Xing, Angew. Chem. Int. Ed., 2022, 61, e202212341.
[61]	X. Zheng, J. Yang, P. Li, Q. Wang, J. Wu, E. Zhang, S. Chen, Z. Zhuang, W. Lai, S. Dou, W. Sun, D. Wang, Y. Li, Sci. Adv., 2023, 9, eadi8025.
[62]	X. Ping, Y. Liu, L. Zheng, Y. Song, L. Guo, S. Chen, Z. Wei, Nat. Commun., 2024, 15, 2501.