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Research Article | Open Access

Hexanuclear nickel-added silicotungstates as high-efficiency electrocatalysts for nitrate reduction to ammonia

Zhihui Ni ( )Ning LiuChunhui ZhaoLiwei Mi ( )
Center for Advanced Materials Research, Henan Key Laboratory of Functional Salt Materials, Zhongyuan University of Technology, Zhengzhou 450007, China
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Ammonia (NH3) is widely used in a wide range of fields because of its high energy density, and NH3 is simple to liquefy and transport. Nitrate is also a source of pollution of the environment and drinking water sources. Therefore, there is a pressing demand for the design and production of high-efficiency catalysts for the nitrate reduction reaction (NO3RR). Herein, two nickel-added polyoxometalates (NiAPs), namely, [Ni(en)2][Ni6(μ3-OH)3(en)3(H2O)6(B-α-SiW9O34)]2·6H2O (Ni6en) and [Ni(enMe)2(H2O)2][Ni6(μ3-OH)3(H2O)6(enMe)3(B-α-SiW9O34)]2·8H2O (Ni6enMe) (en = ethylenediamine, enMe = 1,2-diaminopropane), were effectively synthesized under hydrothermal conditions that contained several electrons and were used as electrocatalytic nitrate reduction reaction (e-NO3RR) catalysts. The structures of the compounds were characterized by using various instruments such as powder X-ray diffraction (PXRD) spectroscopy, infrared (IR) spectroscopy, thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) method, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). e-NO3RR tests were performed using electrochemical workstation. Results show that Ni6en and Ni6enMe have high-efficient electrochemical catalytic nitrogen reduction to NH3. The highest NH3 yield rate for Ni6en was 3.66 mg∙h−1∙mgcat.−1 with Faradaic efficiency (FE) of 89.32%, whereas that for Ni6enMe was 3.46 mg∙h−1∙mgcat.−1 with FE of 86.75% at a low voltage (−0.5 V vs. reversible hydrogen electrode (RHE)). This finding creates a novel path for manufacturing highly effective NO3RR electrocatalysts using metal-added polyoxometalate as the catalyst in ambient settings. Furthermore, the findings of this research provide practical advice for creating effective electrocatalytic catalysts.

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Shukla, S.; Saxena, A. Global status of nitrate contamination in groundwater: Its occurrence, health impacts, and mitigation measures. In Handbook of Environmental Materials Management; Hussain, C. M., Ed.; Springer: Cham, 2019; pp 869–888.

Hsini, A.; Naciri, Y.; Benafqir, M.; Ajmal, Z.; Aarab, N.; Laabd, M.; Navío, J. A.; Puga, F.; Boukherroub, R.; Bakiz, B. et al. Facile synthesis and characterization of a novel 1,2,4,5-benzene tetracarboxylic acid doped polyaniline@zinc phosphate nanocomposite for highly efficient removal of hazardous hexavalent chromium ions from water. J. Colloid Interface Sci. 2021, 585, 560–573.


Wang, L. S.; Fu, W. Z.; Zhuge, Y. P.; Wang, J.; Yao, F. F.; Zhong, W. Z.; Ge, X. H. Synthesis of polyoxometalates (POM)/TiO2/Cu and removal of nitrate nitrogen in water by photocatalysis. Chemosphere 2021, 278, 130298.


Rezvani, F.; Sarrafzadeh, M. H.; Ebrahimi, S.; Oh, H. M. Nitrate removal from drinking water with a focus on biological methods: A review. Environ. Sci. Pollut. Res. Int. 2019, 26, 1124–1141.


Hu, S. H.; Wu, Y. G.; Zhang, Y. J.; Zhou, B.; Xu, X. Nitrate removal from groundwater by heterotrophic/autotrophic denitrification using easily degradable organics and nano-zero valent iron as Co-electron donors. Water Air Soil Pollut. 2018, 229, 56.


Čorić, I.; Mercado, B. Q.; Bill, E.; Vinyard, D. J.; Holland, P. L. Binding of dinitrogen to an iron-sulfur-carbon site. Nature 2015, 526, 96–99.


Licht, S.; Cui, B. C.; Wang, B. H.; Li, F. F.; Lau, J.; Liu, S. Z. RETRACTED: Ammonia synthesis by N2 and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2O3. Science 2014, 345, 637–642.


Guo, K. Y.; Yang, J.; Yu, N.; Luo, L.; Wang, E. T. Biological nitrogen fixation in cereal crops: progress, strategies, and perspectives. Plant Commun. 2023, 4, 100499.


Andersen, S. Z.; Statt, M. J.; Bukas, V. J.; Shapel, S. G.; Pedersen, J. B.; Krempl, K.; Saccoccio, M.; Chakraborty, D.; Kibsgaard, J.; Vesborg, P. C. K. et al. Increasing stability, efficiency, and fundamental understanding of lithium-mediated electrochemical nitrogen reduction. Energy Environ. Sci. 2020, 13, 4291–4300.


Xu, T.; Liang, J.; Wang, Y. Y.; Li, S. X.; Du, Z. B.; Li, T. S.; Liu, Q.; Luo, Y. L.; Zhang, F.; Shi, X. F. et al. Enhancing electrocatalytic N2-to-NH3 fixation by suppressing hydrogen evolution with alkylthiols modified Fe3P nanoarrays. Nano Res. 2022, 15, 1039–1046.


Zhao, X.; Hu, G. Z.; Chen, G. F.; Zhang, H. B.; Zhang, S. S.; Wang, H. H. Comprehensive understanding of the thriving ambient electrochemical nitrogen reduction reaction. Adv. Mater. 2021, 33, 2007650.


Wang, D. D.; Chen, Z. W.; Gu, K. Z.; Chen, C.; Liu, Y. Y.; Wei, X. X.; Singh, C. V.; Wang, S. Y. Hexagonal cobalt nanosheets for high-performance electrocatalytic NO reduction to NH3. J. Am. Chem. Soc. 2023, 145, 6899–6904.


Shi, M. M.; Bao, D.; Li, S. J.; Wulan, B. R.; Yan, J. M.; Jiang, Q. Anchoring PdCu amorphous nanocluster on graphene for electrochemical reduction of N2 to NH3 under ambient conditions in aqueous solution. Adv. Energy Mater. 2018, 8, 1800124.


Hu, B.; Hu, M. W.; Seefeldt, L.; Liu, T. L. Electrochemical dinitrogen reduction to ammonia by Mo2N: Catalysis or decomposition? ACS Energy Lett. 2019, 4, 1053–1054.


Andersen, S. Z.; Čolić, V.; Yang, S.; Schwalbe, J. A.; Nielander, A. C.; McEnaney, J. M.; Enemark-Rasmussen, K.; Baker, J. G.; Singh, A. R.; Rohr, B. A. et al. A rigorous electrochemical ammonia synthesis protocol with quantitative isotope measurements. Nature 2019, 570, 504–508.


Liu, Y. Q.; Huang, L.; Fang, Y. X.; Zhu, X. Y.; Dong, S. J. Achieving ultrahigh electrocatalytic NH3 yield rate on Fe-doped Bi2WO6 electrocatalyst. Nano Res. 2021, 14, 2711–2716.


Shen, H. D.; Yang, M. M.; Hao, L. D.; Wang, J. R.; Strunk, J.; Sun, Z. Y. Photocatalytic nitrogen reduction to ammonia: Insights into the role of defect engineering in photocatalysts. Nano Res. 2022, 15, 2773–2809.


Zhai, X. W.; Yan, H. X.; Ge, G. X.; Yang, J. M.; Chen, F.; Liu, X. Y.; Yang, D. Z.; Li, L. F.; Zhang, J. L. The single-Mo-atom-embedded-graphdiyne monolayer with ultra-low onset potential as high efficient electrocatalyst for N2 reduction reaction. Appl. Surf. Sci. 2020, 506, 144941.


Wang, W. K.; Zhang, S. B.; Liu, Y. Y.; Zheng, L. R.; Wang, G. Z.; Zhang, Y. X.; Zhang, H. M.; Zhao, H. J. Integration of Fe2O3-based photoanode and atomically dispersed cobalt cathode for efficient photoelectrochemical NH3 synthesis. Chin. Chem. Lett. 2021, 32, 805–810.


Li, X. H.; Xue, C.; Zhou, X. R.; Wei, Y. A.; Yu, Y. J.; Fu, Y.; Liu, W. J.; Lan, Y. Q. Polyoxometalate-derived bimetallic catalysts for the nitrogen reduction reaction. Mater. Chem. Front. 2023, 7, 720–727.


Huang, C. X.; Lv, S. Y.; Li, C.; Peng, B.; Li, G. L.; Yang, L. M. Single-atom catalysts based on two-dimensional metalloporphyrin monolayers for ammonia synthesis under ambient conditions. Nano Res. 2022, 15, 4039–4047.


Qi, J. M.; Zhou, S. L.; Xie, K.; Lin, S. Catalytic role of assembled Ce Lewis acid sites over ceria for electrocatalytic conversion of dinitrogen to ammonia. J. Energy Chem. 2021, 60, 249–258.


Zhao, Y. X.; Zhao, Y. F.; Shi, R.; Wang, B.; Waterhouse, G. I. N.; Wu, L. Z.; Tung, C. H.; Zhang, T. R. Tuning oxygen vacancies in ultrathin TiO2 nanosheets to boost photocatalytic nitrogen fixation up to 700 nm. Adv. Mater. 2019, 31, 1806482.


Shang, S. S.; Xiong, W.; Yang, C.; Johannessen, B.; Liu, R. G.; Hsu, H. Y.; Gu, Q. F.; Leung, M. K. H.; Shang, J. Atomically dispersed iron metal site in a porphyrin-based metal-organic framework for photocatalytic nitrogen fixation. ACS Nano 2021, 15, 9670–9678.


Jiao, F.; Xu, B. J. Electrochemical ammonia synthesis and ammonia fuel cells. Adv. Mater. 2019, 31, 1805173.


Liu, Q.; Xu, T.; Luo, Y. L.; Kong, Q. Q.; Li, T. S.; Lu, S. Y.; Alshehri, A. A.; Alzahrani, K. A.; Sun, X. P. Recent advances in strategies for highly selective electrocatalytic N2 reduction toward ambient NH3 synthesis. Curr. Opin. Electrochem. 2021, 29, 100766.


Chen, H. J.; Liang, J.; Dong, K.; Yue, L. C.; Li, T. S.; Luo, Y. S.; Feng, Z. S.; Li, N.; Hamdy, M. S.; Alshehri, A. A. et al. Ambient electrochemical N2-to-NH3 conversion catalyzed by TiO2 decorated juncus effusus-derived carbon microtubes. Inorg. Chem. Front. 2022, 9, 1514–1519.


Bastia, S.; Moses, Y. T.; Kumar, N.; Mishra, R. P.; Chaudhary, Y. S. Enhanced nitrogen reduction to ammonia by surface-and defect-engineered Co-catalyst-modified perovskite catalysts under ambient conditions and their charge carrier dynamics. ACS Appl. Mater. Interfaces 2023, 15, 13052–13063.


Ni, Z. H.; Lv, H. J.; Yang, G. Y. Recent advances of Ti/Zr-substituted polyoxometalates: From structural diversity to functional applications. Molecules 2022, 27, 8799.


Zhang, Z.; Wang, Y. L.; Li, H. L.; Sun, K. N.; Yang, G. Y. Syntheses, structures and properties of three organic-inorganic hybrid polyoxotungstates constructed from {Ni6PW9} building blocks: From isolated clusters to 2-D layers. CrystEngComm 2019, 21, 2641–2647.


Guan, Y.; Xiao, H. P.; Li, X. X.; Zheng, S. T. Recent advances on the synthesis, structure, and properties of polyoxotantalates. Polyoxometalates 2023, 2, 9140023.


Lai, Q. S.; Li, X. X.; Zheng, S. T. All-inorganic POM cages and their assembly: A review. Coordin. Chem. Rev. 2023, 482, 215077.


Sun, J. Y.; Wang, Z. L.; Zhang, Z.; Liu, G. C.; Wang, X. L. Hydrothermal synthesis, structure, and catalytic properties of a (4,6)-connected framework constructed from Keggin-type polyoxometalate units and tetranuclear copper complexes. Polyoxometalates 2024, 3, 9140039.


Zhang, Y.; Wang, X.; Wang, Y.; Xu, N.; Wang, X. L. Anderson-type polyoxometalate-based sandwich complexes bearing a new “V”-like bis-imidazole-bis-amide ligand as electrochemical sensors and catalysts for sulfide oxidation. Polyoxometalates 2022, 1, 9140004.


Yang, L.; Zhang, Z.; Zhang, C. N.; Li, S.; Liu, G. C.; Wang, X. L. An excellent multifunctional photocatalyst with a polyoxometalate-viologen framework for CEES oxidation, Cr(VI) reduction and dye decolorization under different light regimes. Inorg. Chem. Front. 2022, 9, 4824–4833.


Li, X. X.; Zhao, D.; Zheng, S. T. Recent advances in POM-organic frameworks and POM-organic polyhedra. Coord. Chem. Rev. 2019, 397, 220–240.


Li, H. L.; Lian, C.; Yang, G. Y. A Zr-added Dawson-type poly(polyoxometalate). Dalton Trans. 2023, 52, 857–861.

Li, H. L.; Lian, C.; Yang, G. Y. A new 4-Ti-added polyoxometalate. Tungsten, in press, DOI: 10.1007/s42864-023-00221-5.

Lian, C.; Li, H. L.; Yang, G. Y. A new 28-Ni-added poly(polyoxometalate) with B atoms: Synthesis, structure and catalysis for Knoevenagel condensation. Sci. China Chem. 2023, 66, 1394–1399.


Lai, R. D.; Zhang, J.; Li, X. X.; Zheng, S. T.; Yang, G. Y. Assemblies of increasingly large Ln-containing polyoxoniobates and intermolecular aggregation-disaggregation interconversions. J. Am. Chem. Soc. 2022, 144, 19603–19610.


Gao, L. Y.; Wang, F. T.; Yu, M. A.; Wei, F. F.; Qi, J. M.; Lin, S.; Xie, D. Q. A novel phosphotungstic acid-supported single metal atom catalyst with high activity and selectivity for the synthesis of NH3 from electrochemical N2 reduction: A DFT prediction. J. Mater. Chem. A 2019, 7, 19838–19845.


Lin, L. H.; Gao, L. Y.; Xie, K.; Jiang, R.; Lin, S. Ru-polyoxometalate as a single-atom electrocatalyst for N2 reduction to NH3 with high selectivity at applied voltage: A perspective from DFT studies. Phys. Chem. Chem. Phys. 2020, 22, 7234–7240.


Wang, X.; Yang, J.; Salla, M.; Xi, S. B.; Yang, Y.; Li, M. S.; Zhang, F. F.; Zhu, M. K.; Huang, S. P.; Huang, S. Q. et al. Redox-mediated ambient electrolytic nitrogen reduction for hydrazine and ammonia generation. Angew. Chem., Int. Ed. 2021, 60, 18721–18727.


Yang, X.; Li, M. H.; Xu, L.; Li, F. Y. Limitation of WO3 in Zn-Co3O4 nanopolyhedra by the pyrolysis of H3PW12O40@BMZIF: Synergistic effect of heterostructure and oxygen vacancies for enhanced nitrogen fixation. Inorg. Chem. 2023, 62, 8710–8718.


Li, X. H.; Li, H.; Jiang, S. L.; Yang, L.; Li, H. Y.; Liu, Q. L.; Bai, W.; Zhang, Q.; Xiao, C.; Xie, Y. Constructing mimic-enzyme catalyst: Polyoxometalates regulating carrier dynamics of metal-organic frameworks to promote photocatalytic nitrogen fixation. ACS Catal. 2023, 13, 7189–7198.


Su, S. D.; Li, X. M.; Liu, Z. Y.; Ding, W. M.; Cao, Y.; Yang, Y.; Su, Q.; Luo, M. Microchemical environmental regulation of POMs@MIL-101(Cr) promote photocatalytic nitrogen to ammonia. J. Colloid Interface Sci. 2023, 646, 547–554.


Yin, H. Q.; Yang, L. L.; Sun, H.; Wang, H.; Wang, Y. J.; Zhang, M.; Lu, T. B.; Zhang, Z. M. W/Mo-polyoxometalate-derived electrocatalyst for high-efficiency nitrogen fixation. Chin. Chem. Lett. 2023, 34, 107337.


Yang, M. L.; Wang, X. M.; Gómez-García, C. J.; Jin, Z. X.; Xin, J. J.; Cao, X. X.; Ma, H. Y.; Pang, H. J.; Tan, L. C.; Yang, G. X. et al. Efficient electron transfer from an electron-reservoir polyoxometalate to dual-metal-site metal-organic frameworks for highly efficient electroreduction of nitrogen. Adv. Funct. Mater. 2023, 33, 2214495.


Ye, S. H.; Chen, Z. D.; Zhang, G. K.; Chen, W. D.; Peng, C.; Yang, X. Y.; Zheng, L. R.; Li, Y. L.; Ren, X. Z.; Cao, H. Q. et al. Elucidating the activity, mechanism and application of selective electrosynthesis of ammonia from nitrate on cobalt phosphide. Energy Environ. Sci. 2022, 15, 760–770.


Hervé, G.; Tézé, A. Study of ɑ- and β-enneatungstosilicates and-germanates. Inorg. Chem. 1977, 16, 2115–2117.

Sheldrick, G. M. SHELXS-97, program for X-ray crystal structure solution; University of Göttingen, Germany, 1997.

Sheldrick, G. M. Crystal structure refinement with SHELXL. Acta Crystallogr. Sec. C Struct. Chem. 2015, C71, 3–8.


Xu, L. J.; Zhou, W. Z.; Zhang, L. Y.; Li, B.; Zang, H. Y.; Wang, Y. H.; Li, Y. G. Organic-inorganic hybrid assemblies based on Ti-substituted polyoxometalates for photocatalytic dye degradation. CrystEngComm 2015, 17, 3708–3714.


Wang, X. Y.; Bai, J. W.; Wang, Y. T.; Lu, X. Y.; Zou, Z. H.; Huang, J. F.; Xu, C. L. Sulfur vacancies-doped Sb2S3 nanorods as high-efficient electrocatalysts for dinitrogen fixation under ambient conditions. Green Energy Environ. 2022, 7, 755–762.


Li, Y. S.; Wang, H. Y.; Chang, B.; Guo, Y. Y.; Li, Z. Y.; Talib, S. H.; Lu, Z. S.; Wang, J. J. Intercalation assisted liquid phase production of disulfide zirconium nanosheets for efficient electrocatalytic dinitrogen reduction to ammonia. Green Energy Environ. 2023, 8, 1174–1184.


Wan, Y. C.; Zhou, H. J.; Zheng, M. Y.; Huang, Z. H.; Kang, F. Y.; Li, J.; Lv, R. T. Oxidation state modulation of bismuth for efficient electrocatalytic nitrogen reduction to ammonia. Adv. Funct. Mater. 2021, 31, 2100300.


Zhao, J. W.; Jia, H. P.; Zhang, J.; Zheng, S. T.; Yang, G. Y. A combination of lacunary polyoxometalates and high-nuclear transition-metal clusters under hydrothermal conditions. Part II: From double cluster, dimer, and tetramer to three-dimensional frameworks. Chem.—Eur. J. 2007, 13, 10030–10045.


Li, Q. L.; Zhang, Y. P.; Wang, X. X.; Yang, Y. Dual interface-engineered tin heterostructure for enhanced ambient ammonia electrosynthesis. ACS Appl. Mater. Interfaces 2021, 13, 15270–15278.


Zheng, S. T.; Yuan, D. Q.; Jia, H. P.; Zhang, J.; Yang, G. Y. Combination between lacunary polyoxometalates and high-nuclear transition metal clusters under hydrothermal conditions: I. from isolated cluster to 1-D chain. Chem. Commun. 2007, 1858–1860.


Liu, Y.; Zhang, Z.; Li, X. Y.; Yang, G. Y. A Ni11-cluster sandwiched phosphotungstate supported by Ni(H2O)5 group. Inorg. Chem. Commun. 2020, 113, 107765.


Ni, Z. H.; Li, H. L.; Li, X. Y.; Yang, G. Y. Zr4-substituted polyoxometalate dimers decorated by D-tartaric acid/glycolic acid: Syntheses, structures and optical/electrochemical properties. CrystEngComm 2019, 21, 876–883.


Tong, Y. Y.; Guo, H. P.; Liu, D. L.; Yan, X.; Su, P. P.; Liang, J.; Zhou, S.; Liu, J.; Lu, G. Q.; Dou, S. X. Vacancy engineering of iron-doped W18O49 nanoreactors for low-barrier electrochemical nitrogen reduction. Angew. Chem., Int. Ed. 2020, 59, 7356–7361.


Romanyuk, O.; Gordeev, I.; Paszuk, A.; Supplie, O.; Stoeckmann, J. P.; Houdkova, J.; Ukraintsev, E.; Bartoš, I.; Jiříček, P.; Hannappel, T. GaP/Si(0 0 1) interface study by XPS in combination with Ar gas cluster ion beam sputtering. Appl. Surf. Sci. 2020, 514, 145903.


Bagus, P. S.; Nelin, C. J.; Brundle, C. R.; Crist, B. V.; Ilton, E. S.; Lahiri, N.; Rosso, K. M. Main and satellite features in the Ni 2p XPS of NiO. Inorg. Chem. 2022, 61, 18077–18094.


Feng, Z. M.; Li, G.; Wang, X. M.; Gómez-García, C. J.; Xin, J. J.; Ma, H. Y.; Pang, H. J.; Gao, K. Q. FeS2/MoS2@RGO hybrid materials derived from polyoxomolybdate-based metal-organic frameworks as high-performance electrocatalyst for ammonia synthesis under ambient conditions. Chem. Eng. J. 2022, 445, 136797.

Article number: 9140044
Cite this article:
Ni Z, Liu N, Zhao C, et al. Hexanuclear nickel-added silicotungstates as high-efficiency electrocatalysts for nitrate reduction to ammonia. Polyoxometalates, 2024, 3(1): 9140044.








Received: 29 August 2023
Revised: 29 October 2023
Accepted: 21 November 2023
Published: 08 December 2023
© The Author(s) 2023. Published by Tsinghua University Press.

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