Abstract
Renewable electricity-driven electrochemical nitrogen oxidation is a promising alternative to traditional Haber–Bosch and Ostwald processes to directly synthesize nitrate from nitrogen. However, its efficiency is hindered by strong competition from the oxygen evolution reaction in aqueous environments, along with a deficiency in standardized testing protocols. Here we present an efficient approach for nitrogen oxidation, substituting the oxygen evolution reaction with hydroxyl radicals (·OH) generated through hydrogen peroxide decomposition to serve as an active oxygen source. Electrochemical tests demonstrate that the nitrogen oxidation, facilitated by ·OH, can achieve a Faradaic efficiency of 25.6% and a nitrate yield of 8.3 nmol s−1 cm−2. Furthermore, we employed in situ electrochemical mass spectrometry, gas-phase infrared and electron paramagnetic resonance spectroscopy to establish a comprehensive set of benchmarks to confirm the authenticity of nitrogen activation and to examine the reaction mechanism mediated by ·OH. Techno-economic analysis underscores the promising feasibility and sustainable economic value of the presented method.
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Data availability
The data supporting the finding of the study are available in the paper and its Supplementary Information. Source data are provided with this paper and in the Mendeley Data repository at https://doi.org/10.17632/kcwgbv68y6.1 (ref. 50).
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Acknowledgements
This work was supported by the National Natural Science Foundation of China (nos. 22072015 and 21927811), the Free Exploration Project of Frontier Technology for Laoshan Laboratory (no. 16-02), the Program for Science & Technology Innovation Talents in Universities of Henan Province (no. 20HASTIT028) and China Postdoctoral Science Foundation (2023M731175 and GZB20230232). We thank S. Li from Nanjing University of Aeronautics and Astronautics and J. Nie from Jilin University for their invaluable contributions in the initial phases of the experiment. Furthermore, we appreciate X. Wang from Gaossunion Corporation for designing the in situ electrochemical electrolytic cell.
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K.D. performed the catalyst preparation, characterizations and catalytic tests. D.M. and Haobo Li conceived and conducted the theoretical investigation of the nitrogen oxidation mechanism. K.D., Y.Y., Huangjingwei Li, S.S., Y.W., Y.L., D.Z. and Qian Liu contributed to the structure characterizations and data analysis. K.D., Quan Li, D.M., X.S. and B.T. designed this study and wrote the paper. All authors contributed and reviewed the paper.
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Dong, K., Yao, Y., Li, H. et al. H2O2-mediated electrosynthesis of nitrate from air. Nat. Synth (2024). https://doi.org/10.1038/s44160-024-00522-8
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DOI: https://doi.org/10.1038/s44160-024-00522-8