Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Photocatalytic nitrogen fixation under an ambient atmosphere using a porous coordination polymer with bridging dinitrogen anions


The design of highly electron-active and stable heterogeneous catalysts for the ambient nitrogen reduction reaction is challenging due to the inertness of the N2 molecule. Here, we report the synthesis of a zinc-based coordination polymer that features bridging dinitrogen anionic ligands, {[Zn(L)(N2)0.5(TCNQ–TCNQ)0.5]·(TCNQ)0.5}n (L is tetra(isoquinolin-6-yl)tetrathiafulvalene and TCNQ is tetracyanoquinodimethane), and show that it is an efficient photocatalyst for nitrogen fixation under an ambient atmosphere. It exhibits an ammonia conversion rate of 140 μmol g−1 h−1 and functions well also with unpurified air as the feeding gas. Experimental and theoretical studies show that the active [Zn2+–(N≡N)–Zn2+] sites can promote the formation of NH3 and the detachment of the NH3 formed creates unsaturated [Zn2+···Zn+] intermediates, which in turn can be refilled by external N2 sequestration and fast intermolecular electron migration. The [Zn2+···Zn+] intermediates stabilized by the sandwiched cage-like donor–acceptor–donor framework can sustain continuous catalytic cycles. This work presents an example of a molecular active site embedded within a coordination polymer for nitrogen fixation under mild conditions.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Single crystal structure of NJUZ-1.
Fig. 2: Spectroscopy characterizations and spin-density distributions of NJUZ-1.
Fig. 3: Absorption characterizations and NRR performances of NJUZ-1.
Fig. 4: Characterizations of NJUZ-1 during and after the NRR process.
Fig. 5: Possible NRR pathways of NJUZ-1.

Similar content being viewed by others

Data availability

All experimental details and data supporting the findings of this study are available within the paper and its Supplementary Information. The data are also available from the corresponding authors upon reasonable request. Crystallographic data for the NJUZ-1 structure have been deposited at the Cambridge Crystallographic Data Centre, under deposition number CCDC 2008863. Copies of the data can be obtained free of charge via Source data are provided with this paper.


  1. Ertl, G. Reactions at surfaces: from atoms to complexity (Nobel Lecture). Angew. Chem. Int. Ed. 47, 3524–3535 (2008).

    Article  CAS  Google Scholar 

  2. Foster, S. L. et al. Catalysts for nitrogen reduction to ammonia. Nat. Catal. 1, 490–500 (2018).

    Article  Google Scholar 

  3. Jia, H.-P. & Quadrelli, E. A. Mechanistic aspects of dinitrogen cleavage and hydrogenation to produce ammonia in catalysis and organometallic chemistry: relevance of metal hydride bonds and dihydrogen. Chem. Soc. Rev. 43, 547–564 (2014).

    Article  CAS  Google Scholar 

  4. Hinchliffe, A (ed.) Chemical Modelling: Applications and Theory Vol. 5 (RSC Publishing, 2009).

  5. Rayment, T., Schlögl, R., Thomas, J. M. & Ertl, G. Structure of the ammonia synthesis catalyst. Nature 315, 311–313 (1985).

    Article  CAS  Google Scholar 

  6. Zhou, F. et al. Electro-synthesis of ammonia from nitrogen at ambient temperature and pressure in ionic liquids. Energy Environ. Sci. 10, 2516–2520 (2017).

    Article  CAS  Google Scholar 

  7. Ithisuphalap, K. et al. Photocatalysis and photoelectrocatalysis methods of nitrogen reduction for sustainable ammonia synthesis. Small Methods 3, 1800352 (2019).

    Article  Google Scholar 

  8. MacKay, B. A. & Fryzuk, M. D. Dinitrogen coordination chemistry: on the biomimetic borderlands. Chem. Rev. 104, 385–402 (2004).

    Article  CAS  Google Scholar 

  9. Hoffman, B. M., Lukoyanov, D., Yang, Z.-Y., Dean, D. R. & Seefeldt, L. C. Mechanism of nitrogen fixation by nitrogenase: the next stage. Chem. Rev. 114, 4041–4062 (2014).

    Article  CAS  Google Scholar 

  10. Zhang, Y., Zuo, J.-L., Zhou, H.-C. & Holm, R. H. Rearrangement of symmetrical dicubane clusters into topological analogues of the P cluster of nitrogenase: nature’s choice? J. Am. Chem. Soc. 124, 14292–14293 (2002).

    Article  CAS  Google Scholar 

  11. Yandulov, D. V. & Schrock, R. R. Catalytic reduction of dinitrogen to ammonia at a single molybdenum center. Science 301, 76–78 (2003).

    Article  CAS  Google Scholar 

  12. Arashiba, K., Miyake, Y. & Nishibayashi, Y. A molybdenum complex bearing PNP-type pincer ligands leads to the catalytic reduction of dinitrogen into ammonia. Nat. Chem. 3, 120–125 (2011).

    Article  CAS  Google Scholar 

  13. Anderson, J. S., Rittle, J. & Peters, J. C. Catalytic conversion of nitrogen to ammonia by an iron model complex. Nature 501, 84–87 (2013).

    Article  CAS  Google Scholar 

  14. Chalkley, M. J., Drover, M. W. & Peters, J. C. Catalytic N2-to-NH3 (or -N2H4) conversion by well-defined molecular coordination complexes. Chem. Rev. 120, 5582–5636 (2020).

    Article  CAS  Google Scholar 

  15. Roux, Y., Duboc, C. & Gennari, M. Molecular catalysts for N2 reduction: state of the art, mechanism, and challenges. Chem. Phys. Chem. 18, 2606–2617 (2017).

    Article  CAS  Google Scholar 

  16. Yang, Q., Xu, Q. & Jiang, H.-L. Metal–organic frameworks meet metal nanoparticles: synergistic effect for enhanced catalysis. Chem. Soc. Rev. 46, 4774–4808 (2017).

    Article  CAS  Google Scholar 

  17. Wang, H.-Y. et al. Functional coordination polymers based on redox-active tetrathiafulvalene and its derivatives. Coord. Chem. Rev. 345, 342–361 (2017).

    Article  CAS  Google Scholar 

  18. Jiao, L., Wang, Y., Jiang, H.-L. & Xu, Q. Metal–organic frameworks as platforms for catalytic applications. Adv. Mater. 30, 1703663 (2018).

    Article  Google Scholar 

  19. Mars, P. & van Krevelen, D. W. Oxidations carried out by means of vanadium oxide catalysts. Chem. Eng. Sci. 3, 41–59 (1954).

    Article  CAS  Google Scholar 

  20. Blatov, V. A., Shevchenko, A. P. & Proserpio, D. M. Applied topological analysis of crystal structures with the program package ToposPro. Cryst. Growth Des. 14, 3576–3586 (2014).

    Article  CAS  Google Scholar 

  21. Kim, J., Silakov, A., Yennawar, H. P. & Lear, B. J. Structural, electronic, and magnetic characterization of a dinuclear zinc complex containing TCNQ and a μ–[TCNQ–TCNQ]2− ligand. Inorg. Chem. 54, 6072–6074 (2015).

    Article  CAS  Google Scholar 

  22. Kuriyama, S., Arashiba, K., Yoshizawa, K. & Nishibayashi, Y. Catalytic formation of ammonia from molecular dinitrogen by use of dinitrogen-bridged dimolybdenum–dinitrogen complexes bearing PNP-pincer ligands: remarkable effect of substituent at PNP-pincer ligand. J. Am. Chem. Soc. 136, 9719–9731 (2014).

    Article  CAS  Google Scholar 

  23. Coffinet, A., Simonneau, A. & Specklin, D. in Encyclopedia of Inorganic and Bioinorganic Chemistry (ed. Scott, R. A.) 1–25 (John Wiley & Sons, 2020).

  24. Gallagher, N. M., Bauer, J. J., Pink, M., Rajca, S. & Rajca, A. High-spin organic diradical with robust stability. J. Am. Chem. Soc. 138, 9377–9380 (2016).

    Article  CAS  Google Scholar 

  25. Wilson, A. Tables of interatomic distances and configuration in molecules and ions. Acta Cryst. 12, 174 (1959).

    Google Scholar 

  26. Li, M. et al. Recent progress on electrocatalyst and photocatalyst design for nitrogen reduction. Small Methods 3, 1800388 (2019).

    Article  Google Scholar 

  27. Hirakawa, H., Hashimoto, M., Shiraishi, Y. & Hirai, T. Photocatalytic conversion of nitrogen to ammonia with water on surface oxygen vacancies of titanium dioxide. J. Am. Chem. Soc. 139, 10929–10936 (2017).

    Article  CAS  Google Scholar 

  28. Ashida, Y., Arashiba, K., Nakajima, K. & Nishibayashi, Y. Molybdenum-catalysed ammonia production with samarium diiodide and alcohols or water. Nature 568, 536–540 (2019).

    Article  CAS  Google Scholar 

  29. Cui, P. et al. A multicentre-bonded [ZnI]8 cluster with cubic aromaticity. Nat. Commun. 6, 6331 (2015).

    Article  CAS  Google Scholar 

  30. Narayan, T. C., Miyakai, T., Seki, S. & Dincă, M. High charge mobility in a tetrathiafulvalene-based microporous metal–organic framework. J. Am. Chem. Soc. 134, 12932–12935 (2012).

    Article  CAS  Google Scholar 

  31. Su, J. et al. High electrical conductivity in a 2D MOF with intrinsic superprotonic conduction and interfacial pseudo-capacitance. Matter 2, 711–722 (2020).

    Article  Google Scholar 

  32. Alves, H., Molinari, A. S., Xie, H. & Morpurgo, A. F. Metallic conduction at organic charge-transfer interfaces. Nat. Mater. 7, 574–580 (2008).

    Article  CAS  Google Scholar 

  33. Bhutto, S. M. & Holland, P. L. Dinitrogen activation and functionalization using β-diketiminate iron complexes. Eur. J. Inorg. Chem. 2019, 1861–1869 (2019).

    Article  CAS  Google Scholar 

  34. Grimme, S., Antony, J., Ehrlich, S. & Krieg, H. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys. 132, 154104 (2010).

    Article  Google Scholar 

  35. Materials Studio v.7.0 (Accelrys, 2013).

  36. Nørskov, J. K. et al. Origin of the overpotential for oxygen reduction at a fuel-cell cathode. J. Phys. Chem. B 108, 17886–17892 (2004).

    Article  Google Scholar 

  37. Frisch, M. J. et al. Gaussian 16, revision A.03 (Gaussian Inc., 2016).

  38. Tomasi, J., Mennucci, B. & Cammi, R. Quantum mechanical continuum solvation models. Chem. Rev. 105, 2999–3094 (2005).

    Article  CAS  Google Scholar 

  39. Becke, A. D. Density-functional exchange-energy approximation with correct asymptotic behavior. Phys. Rev. A 38, 3098–3100 (1988).

    Article  CAS  Google Scholar 

  40. Perdew, J. P. Density-functional approximation for the correlation energy of the inhomogeneous electron gas. Phys. Rev. B 33, 8822–8824 (1986).

    Article  CAS  Google Scholar 

  41. Schäfer, A., Horn, H. & Ahlrichs, R. Fully optimized contracted Gaussian basis sets for atoms Li to Kr. J. Chem. Phys. 97, 2571–2577 (1992).

    Article  Google Scholar 

  42. Zhao, Y. & Truhlar, D. G. A new local density functional for main-group thermochemistry, transition metal bonding, thermochemical kinetics, and noncovalent interactions. J. Chem. Phys. 125, 194101 (2006).

    Article  Google Scholar 

  43. Weigend, F. & Ahlrichs, R. Balanced basis sets of split valence, triple zeta valence and quadruple zeta valence quality for H to Rn: Design and assessment of accuracy. Phys. Chem. Chem. Phys. 7, 3297–3305 (2005).

    Article  CAS  Google Scholar 

  44. Delley, B. From molecules to solids with the DMol3 approach. J. Chem. Phys. 113, 7756–7764 (2000).

    Article  CAS  Google Scholar 

  45. Segall, M. D. et al. First-principles simulation ideas, illustrations and the CASTEP code. J. Phys. Condens. Matter 14, 2717 (2002).

    Article  CAS  Google Scholar 

  46. Roy, L. et al. Reduction of CO2 by a masked two-coordinate cobalt(I) complex and characterization of a proposed oxodicobalt(II) intermediate. Chem. Sci. 10, 918–929 (2019).

    Article  CAS  Google Scholar 

  47. Légaré, M. A. et al. The reductive coupling of dinitrogen. Science 363, 1329–1332 (2019).

    Article  Google Scholar 

  48. Li, S., Ma, J. & Jiang, Y. Linear scaling local correlation approach for solving the coupled cluster equations of large systems. J. Comput. Chem. 23, 237–244 (2002).

    Article  CAS  Google Scholar 

  49. Ni, Z., Guo, Y., Neese, F., Li, W. & Li, S. Cluster-in-molecule local correlation method with an accurate distant pair correction for large systems. J. Chem. Theory Comput. 17, 756–766 (2021).

    Article  CAS  Google Scholar 

  50. Ni, Z., Li, W. & Li, S. Fully optimized implementation of the cluster-in-molecule local correlation approach for electron correlation calculations of large systems. J. Comput. Chem. 40, 1130–1140 (2019).

    Article  CAS  Google Scholar 

  51. Guo, Y., Becker, U. & Neese, F. Comparison and combination of “direct” and fragment based local correlation methods: Cluster in molecules and domain-based local pair natural orbital perturbation and coupled cluster theories. J. Chem. Phys. 148, 124117 (2018).

    Article  Google Scholar 

  52. Li, W., Chen, C., Zhao, D. & Li, S. LSQC: Low scaling quantum chemistry program. Int. J. Quantum Chem. 115, 641–646 (2015).

    Article  CAS  Google Scholar 

  53. Neese, F., Wennmohs, F., Becker, U. & Riplinger, C. The ORCA quantum chemistry program package. J. Chem. Phys. 152, 224108 (2020).

    Article  CAS  Google Scholar 

Download references


This work was supported by the National Key Research and Development Program (2018YFA0306004 and 2017YFA0208200), the National Natural Science Foundation of China (22022505, 22033004, 21875099, 21872069 and 21631006), the Fundamental Research Funds for the Central Universities of China (020514380266, 020514380272 and 020514380274), the Scientific and Technological Innovation Special Fund for Carbon Peak and Carbon Neutrality of Jiangsu Province (BK20220008), the Nanjing International Collaboration Research Program (202201007 and 2022SX00000955) and the Suzhou Gusu Leading Talent Program of Science and Technology Innovation and Entrepreneurship in Wujiang District (ZXL2021273).

Author information

Authors and Affiliations



Y.X., B.L. J.-L.Z. and Z.J. conceived the idea of this study and designed the experiments. Y.X. and B.L. performed the sample synthesis, material characterizations, photoelectric measurements, photocatalytic tests and data analysis. Y.G., Z.N., S.L. and J.M. performed the theoretical calculations. All the authors analysed the data and discussed the results. Y.X., B.L., J.M. Z.J. and J.-L.Z. co-wrote and revised the manuscript. Z.J. and J.-L.Z. supervised the project.

Corresponding authors

Correspondence to Jing-Lin Zuo, Jing Ma or Zhong Jin.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Chemistry thanks the anonymous reviewers for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Synthetic process and 1H-NMR analysis of L.

a Schematic synthetic process of L ligand. b 1H-NMR spectrum of CDCl3 dissolved L ligand.

Extended Data Fig. 2 Schematic structure diagram of NJUZ-1.

a (2, 4, 6) 3-nodal simplified 3D topological network of NJUZ-1. b The 2D layered structure of NJUZ-1 viewed along the b axis. c The interactions of π···π stacking and C-H···N hydrogen bonds in the cage of [(L)2(Zn2N2)4].

Extended Data Fig. 3 Spectroscopy and EPR characterizations of NJUZ-1.

a The IR spectra measured in air (black curve) and vacuum (dark cyan curve). The two split peaks at around 2100 cm−1 are attributed to the cyano groups in TCNQ. b Simulated IR spectrum of C≡N bonds in NJUZ-1 calculated by DFT at level1. c Raman spectra of 14N-NJUZ-1 and 15N-NJUZ-1. The peak at ~2005 cm−1 is dinitrogen complexes for 14N-NJUZ-1. As for 15N-NJUZ-1, the 15N≡15N stretching vibration is at ~1920 cm−1, with a small red shift (~80 cm−1) compared to that of 14N-NJUZ-1. The peaks at 2224, 2203 and 2192 cm−1 are derived from the cyano groups in TCNQ. d Simulated Raman spectrum of Zn-C≡N-Zn structure calculated by DFT at level1. The insert shows the proposed Zn-C≡N-Zn structure. e Experimental solid EPR spectrum at low temperature (93 K) compared with simulated EPR spectrum (ν = 9.4452 GHz). f Experimental solid EPR spectrum of 15N-NJUZ-1 measured at room temperature (ν = 9.8519 GHz). a.u. refers to absorbance unit.

Source data

Extended Data Fig. 4 Spin-density distributions of cluster models and PBC models.

a cluster models and b PBC models. The values of spin-populations (isovalue = 0.005) on N2 ligands are given in square brackets.

Extended Data Fig. 5 Spin-density distributions of different reaction intermediates at reaction sites (ClusterA models).

The values of spin-populations (isovalue = 0.005) on N2 ligands are given in square brackets.

Extended Data Fig. 6 Structure characterizations of NJUZ-1.

a Representative TEM image of NJUZ-1. b Typical AFM image and the corresponding height profiles of NJUZ-1. c N2 adsorption isotherm of NJUZ-1 at room temperature.

Source data

Extended Data Fig. 7 TDDFT calculations of excitation energies.

a UV-Vis spectrum and fingertip aspects of NJUZ-1. b ClusterA and ClusterB models, which were built from NJUZ-1 crystal. c The TDDFT calculated orbital energy levels of ClusterA. d The TDDFT calculated orbital energy levels of ClusterB. a.u. refers to arbitrary unit.

Extended Data Fig. 8 NRR performances and structure characterizations of NJUZ-1.

a The percentage of ammonia yield rate of NJUZ-1 with unpurified air flow compared to that with N2 flow. b Total ammonia yield of NJUZ-1 after a long-term NRR process for 25 h. c Typical gas chromatograph spectrum (measured by TCD detector) of the gas byproducts yielded during the NRR process catalyzed by NJUZ-1. d XRD patterns of NJUZ-1 before and after 3, 10 and 25 h of the NRR in comparison with the simulated XRD pattern, respectively. e and f Typical TEM image of NJUZ-1 after the NRR for 3 and 10 h, respectively. g Nitrogen adsorption-desorption isotherms of representative NJUZ-1 before and after the NRR test for 25 h. a.u. refers to arbitrary unit.

Source data

Extended Data Fig. 9 Isotope labelling experiments and spin-density distributions with water in ClusterA.

a 1H NMR spectrum of the products measured from 15N-NJUZ-1 after the NRR process for 20 h under Ar atmosphere. b 2H and 1H-NMR analyses of ND3 product after the NRR process of NJUZ-1 in D2O. c Spin-density distributions in ClusterA models with H2O adsorption. The values of spin-populations (isovalue = 0.005) on N2 ligands are given in square brackets. d Solid-state NMR analyses of standard 15NH4Cl sample (black curve) and the NJUZ-1 photocatalyst after the NRR process with 15N2 feeding gas for 20 h (dark cyan curve).

Extended Data Fig. 10 Schematic crystal structure and proposed NRR reaction pathways over NJUZ-1.

a Schematic crystal structure of NJUZ-1. The purple, grey, blue, yellow, and white balls are corresponding to Zn, C, N, S, and H atoms, respectively. b Gibbs free energy profile of the NRR process over NJUZ-1 with alternating (blue), mixed (green) and distal (grey) pathways. c Proposed reaction pathways for the NRR process over NJUZ-1. d Charge variation of the N2-mHn species along the possible alternating, mixed and distal pathways, respectively.

Source data

Supplementary information

Supplementary Information

Supplementary Figs. 1–7 and Supplementary Tables 1–10.

Supplementary Data

Crystallographic data for NJUZ-1, CCDC 2008863.

Source data

Source Data Fig. 2a

Simulated Raman spectra data of Zn–N2–Zn structure.

Source Data Fig. 2b

Raman spectra data of 14N-NJUZ-1 and 15N-NJUZ-1.

Source Data Fig. 2c

EPR spectrum data of NJUZ-1.

Source Data Fig. 3c

Ammonia yield data with N2, unpurified air, Ar or O2 flow.

Source Data Fig. 3d

Ammonia yield data for 10 h with N2 flow.

Source Data Fig. 4b

Raman spectra data of NJUZ-1 measured at pristine state (saturated) and during the NRR process (unsaturated).

Source Data Extended Data Fig. 3a

IR spectra data of NJUZ-1 in air (black curve) and vacuum (dark cyan curve).

Source Data Extended Data Fig. 3b

Simulated IR spectrum data of C≡N bonds in NJUZ-1.

Source Data Extended Data Fig. 3c

Full Raman spectra data of 14N-NJUZ-1 and 15N-NJUZ-1.

Source Data Extended Data Fig. 3d

Simulated Raman spectrum data of Zn–C≡N–Zn structure.

Source Data Extended Data Fig. 3e

Experimental and simulated EPR spectrum data at low temperature (93 K) of NJUZ-1.

Source Data Extended Data Fig. 3f

EPR spectrum data of 15N-NJUZ-1.

Source Data Extended Data Fig. 6c

N2 adsorption isotherms data of NJUZ-1.

Source Data Extended Data Fig. 8a

Percentage of ammonia yield data with Air to N2 flow.

Source Data Extended Data Fig. 8b

25 h long-term ammonia yield data with N2 flow.

Source Data Extended Data Fig. 8d

XRD data of NJUZ-1 before and after 3, 10 and 25 h of the NRR in comparison with the simulated XRD pattern.

Source Data Extended Data Fig. 8g

Nitrogen adsorption–desorption isotherms data of NJUZ-1 before and after 25 test.

Source Data Extended Data Fig. 10d

Charge variation data of the N2-mHn species along the possible alternating, mixed and distal pathways.

Source Data Supplementary Fig. 2

TGA data of NJUZ-1.

Source Data Supplementary Fig. 6

Standard calibration data of NH4+.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Xiong, Y., Li, B., Gu, Y. et al. Photocatalytic nitrogen fixation under an ambient atmosphere using a porous coordination polymer with bridging dinitrogen anions. Nat. Chem. 15, 286–293 (2023).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing