Abstract
The biggest obstacle to the commercialization of protonic ceramic fuel cells (PCFCs) is the lack of high-performance, low-cost cathode materials. Currently, the most promising cathode materials are cobalt-based perovskites; however, the unstable phases, poor thermomechanical compatibility with other PCFC components, high cost and unsatisfactory performance limit the viability of these materials. Here we combine ab initio simulations, molecular orbital insights, and A- and B-site co-substitution to develop a cobalt-free perovskite with outstanding performance. A- and B-site substitution in BaFeO3−δ, is found to promote the formation of oxygen vacancies (\({{{\mathrm{V}}}}_{{{\mathrm{O}}}}^{ \bullet \bullet }\)) and hydroxyl ions (\({{{\mathrm{OH}}}}_{{{\mathrm{O}}}}^ \bullet\)) while retaining structural stability. The best computationally identified material, Ba0.875Fe0.875Zr0.125O3−δ, showed exceptional oxygen reduction reaction electrochemical activity with a peak power density of 0.67 W cm−2 at 500 °C. This rational approach provides a strategy for designing high-activity, low-cost and cobalt-free perovskites, marking a significant step towards realizing commercially viable PCFCs.
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Data availability
The data that support the findings of this study are available within the article and its Supplementary Information files or from the corresponding author upon reasonable request. The atomic coordinates of the optimized structures are provided in Supplementary Data 1. Source data are provided with this paper.
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Acknowledgements
The authors gratefully acknowledge the Research Grant Council of Hong Kong for support through the projects (16201820 and 16206019, received by F.C.), the Nano & Material Technology Development Project (NRF-2021M3H4A1A01002919, received by F.C.) and the Global PhD Fellowship through the National Research Foundation (NRF) of Korea, funded by the Ministry of Science, ICT, and Future Planning (NRF-2018H1A2A1060644, received by A.S.). This work was supported in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone (HZQB-KCZYB-2020083, received by F.C.). M.J.R. and A.B. kindly recognize the support of the Hong Kong PhD Fellowship Scheme. We are grateful to the Materials Characterization and Preparation Facility (MCPF) and the Advanced Engineering Materials Facility (AEMF) of the Hong Kong University of Science and Technology for their assistance in experimental characterizations. The calculations were performed on the Tianhe-2 supercomputer system in Guangzhou.
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Z.W., Y.W. and F.C. conceived and designed the project. Z.W. performed theoretical calculations. Y.W. fabricated fuel cells and performed X-ray diffraction and SEM analyses. Y.S., M.Y., A.S., G.K. and Z.S. measured proton conductivity. J.W. and J.Lim performed X-ray absorption spectroscopy characterizations and contributed to data analysis. Z.Z., A.B. and J.Liu performed TEM characterizations. Z.W., Y.W., Y.S., M.J.R. and F.C. drafted the manuscript. All authors reviewed the manuscript.
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Supplementary Figs. 1–42, Tables 1–12, methods and references.
Supplementary Data
Contains the coordinates of the calculated species in this article.
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Source Data Fig. 1
Contains the energies of calculated species.
Source Data Fig. 2
Contains the energies of calculated species.
Source Data Fig. 3
The projected density of state of Fe–O, Zr–O and Y–O bonds
Source Data Fig. 5
Contains the energies of calculated intermediates of oxygen reduction reactions for BFZ, BFZ-1Vo, BFZ-2Vo and BFZ-2Vo-2OHo
Source Data Fig. 6
The data used to plot the figures.
Source Data Fig. 7
The data used to plot the figures.
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Wang, Z., Wang, Y., Wang, J. et al. Rational design of perovskite ferrites as high-performance proton-conducting fuel cell cathodes. Nat Catal 5, 777–787 (2022). https://doi.org/10.1038/s41929-022-00829-9
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DOI: https://doi.org/10.1038/s41929-022-00829-9
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