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Selective electrocatalytic synthesis of urea with nitrate and carbon dioxide


Synthetic nitrogen fertilizer such as urea has been key to increasing crop productivity and feeding a growing population. However, the conventional urea production relies on energy-intensive processes, consuming approximately 2% of annual global energy. Here, we report on a more-sustainable electrocatalytic approach that allows for direct and selective synthesis of urea from nitrate and carbon dioxide with an indium hydroxide catalyst at ambient conditions. Remarkably, Faradaic efficiency, nitrogen selectivity and carbon selectivity reach 53.4%, 82.9% and ~100%, respectively. The engineered surface semiconducting behaviour of the catalyst is found to suppress hydrogen evolution reaction. The key step of C–N coupling initiates through the reaction between *NO2 and *CO2 intermediates owing to the low energy barrier on {100} facets. This work suggests an appealing route of urea production and provides deep insight into the underlying chemistry of C–N coupling reaction that could guide sustainable synthesis of other indispensable chemicals.

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Fig. 1: Structural characterizations of In(OH)3-S electrocatalyst.
Fig. 2: Electrochemical properties.
Fig. 3: Semiconductor type analysis on In(OH)3-S.
Fig. 4: DFT calculations.
Fig. 5: Operando SR-FTIR spectroscopy measurements under various potentials for In(OH)3-S during electrocatalytic coupling of nitrate and carbon dioxide.

Data availability

All data that support the findings in this paper are available within the article and its Supplementary Information. Source data are available from the corresponding author upon reasonable request.


  1. 1.

    Zhang, X. et al. Managing nitrogen for sustainable development. Nature 528, 51–59 (2015).

    CAS  Article  Google Scholar 

  2. 2.

    Giddey, S., Badwal, S. P. S. & Kulkarni, A. Review of electrochemical ammonia production technologies and materials. Int. J. Hydrogen Energy 38, 14576–14594 (2013).

    CAS  Article  Google Scholar 

  3. 3.

    Martín, A. J., Shinagawa, T. & Pérez-Ramírez, J. Electrocatalytic reduction of nitrogen: from Haber–Bosch to ammonia artificial leaf. Chem 5, 263–283 (2019).

    Article  CAS  Google Scholar 

  4. 4.

    Chen, J. G. et al. Beyond fossil fuel-driven nitrogen transformations. Science 360, eaar6611 (2018).

    Article  CAS  Google Scholar 

  5. 5.

    Suryanto, B. H. et al. Challenges and prospects in the catalysis of electroreduction of nitrogen to ammonia. Nat. Catal. 2, 290–296 (2019).

    CAS  Article  Google Scholar 

  6. 6.

    Hao, Y. C. et al. Promoting nitrogen electroreduction to ammonia with bismuth nanocrystals and potassium cations in water. Nat. Catal. 2, 448–456 (2019).

    CAS  Article  Google Scholar 

  7. 7.

    Lv, C. et al. Boosting electrocatalytic ammonia production through mimicking “π back-donation”. Chem 6, 2690–2702 (2020).

    CAS  Article  Google Scholar 

  8. 8.

    Wang, Y. et al. Generating defect-rich bismuth for enhancing the rate of nitrogen electroreduction to ammonia. Angew. Chem. Int. Ed. 58, 9464–9469 (2019).

    CAS  Article  Google Scholar 

  9. 9.

    Xue, Z.-H. et al. Electrochemical reduction of N2 into NH3 by donor-acceptor couples of Ni and Au nanoparticles with a 67.8% Faradaic efficiency. J. Am. Chem. Soc. 141, 14976–14980 (2019).

    CAS  Article  Google Scholar 

  10. 10.

    Fang, Z., Wu, P., Qian, Y. & Yu, G. Gel-derived amorphous bismuth–nickel alloy promotes electrocatalytic nitrogen fixation via optimizing nitrogen adsorption and activation. Angew. Chem. Int. Ed. 60, 4275–4281 (2021).

    CAS  Article  Google Scholar 

  11. 11.

    Liu, S. et al. Facilitating nitrogen accessibility to boron-rich covalent organic frameworks via electrochemical excitation for efficient nitrogen fixation. Nat. Commun. 10, 3898 (2019).

    Article  CAS  Google Scholar 

  12. 12.

    Liu, Q. et al. Crystalline red phosphorus nanoribbons: large-scale synthesis and electrochemical nitrogen fixation. Angew. Chem. Int. Ed. 59, 14383–14387 (2020).

    CAS  Article  Google Scholar 

  13. 13.

    Lv, C. et al. Defect engineering metal-free polymeric carbon nitride electrocatalyst for effective nitrogen fixation under ambient conditions. Angew. Chem. Int. Ed. 57, 10246–10250 (2018).

    CAS  Article  Google Scholar 

  14. 14.

    Chen, C. et al. Coupling N2 and CO2 in H2O to synthesize urea under ambient conditions. Nat. Chem. 12, 717–724 (2020).

    CAS  Article  Google Scholar 

  15. 15.

    Kayan, D. B. & Köleli, F. Simultaneous electrocatalytic reduction of dinitrogen and carbon dioxide on conducting polymer electrodes. Appl. Catal. B 181, 88–93 (2016).

    CAS  Article  Google Scholar 

  16. 16.

    Wu, Y., Zhang, J., Lin, Z., Liang, Y. & Wang, H. Direct electrosynthesis of methylamine from carbon dioxide and nitrate. Nat. Sustain. (2021).

  17. 17.

    Chen, G.-F. et al. Electrochemical reduction of nitrate to ammonia via direct eight-electron transfer using a copper–molecular solid catalyst. Nat. Energy 5, 605–613 (2020).

    CAS  Article  Google Scholar 

  18. 18.

    Wang, Y. et al. Enhanced nitrate-to-ammonia activity on copper–nickel alloys via tuning of intermediate adsorption. J. Am. Chem. Soc. 142, 5702–5708 (2020).

    CAS  Article  Google Scholar 

  19. 19.

    Li, J. et al. Efficient ammonia electrosynthesis from nitrate on strained ruthenium nanoclusters. J. Am. Chem. Soc. 142, 7036–7046 (2020).

    CAS  Article  Google Scholar 

  20. 20.

    Wang, Y., Zhou, W., Jia, R., Yu, Y. & Zhang, B. Unveiling the activity origin of a copper-based electrocatalyst for selective nitrate reduction to ammonia. Angew. Chem. Int. Ed. 59, 5350–5354 (2020).

    CAS  Article  Google Scholar 

  21. 21.

    Saravanakumar, D., Song, J., Lee, S., Hur, N. H. & Shin, W. Electrocatalytic conversion of carbon dioxide and nitrate ions to urea by a titania–Nafion composite electrode. ChemSusChem 10, 3999–4003 (2017).

    CAS  Article  Google Scholar 

  22. 22.

    Shibata, M. & Furuya, N. Electrochemical synthesis of urea at gas-diffusion electrodes: part VI. Simultaneous reduction of carbon dioxide and nitrite ions with various metallophthalocyanine catalysts. J. Electroanal. Chem. 507, 177–184 (2001).

    CAS  Article  Google Scholar 

  23. 23.

    Shibata, M., Yoshida, K. & Furuya, N. Electrochemical synthesis of urea on reduction of carbon dioxide with nitrate and nitrite ions using Cu-loaded gas-diffusion electrode. J. Electroanal. Chem. 387, 143–145 (1995).

    Article  Google Scholar 

  24. 24.

    Siva, P., Prabu, P., Selvam, M., Karthik, S. & Rajendran, V. Electrocatalytic conversion of carbon dioxide to urea on nano-FeTiO3 surface. Ionics 23, 1871–1878 (2017).

    CAS  Article  Google Scholar 

  25. 25.

    Feng, Y. et al. Te-doped Pd nanocrystal for electrochemical urea production by efficiently coupling carbon dioxide reduction with nitrite reduction. Nano Lett. 11, 8282–8289 (2020).

    Article  CAS  Google Scholar 

  26. 26.

    Cao, N. et al. Oxygen vacancies enhanced cooperative electrocatalytic reduction of carbon dioxide and nitrite ions to urea. J. Colloid Interface Sci. 577, 109–114 (2020).

    CAS  Article  Google Scholar 

  27. 27.

    Liu, J. et al. Controllable and facile synthesis of nearly monodisperse 18-facet indium hydroxide polyhedra. New J. Chem. 39, 1930–1937 (2015).

    CAS  Article  Google Scholar 

  28. 28.

    Yan, T. et al. Bismuth atom tailoring of indium oxide surface frustrated Lewis pairs boosts heterogeneous CO2 photocatalytic hydrogenation. Nat. Commun. 11, 6095 (2020).

    CAS  Article  Google Scholar 

  29. 29.

    Golovanov, V. et al. Experimental and theoretical studies of indium oxide gas sensors fabricated by spray pyrolysis. Sens. Actuators B 106, 563–571 (2005).

    CAS  Article  Google Scholar 

  30. 30.

    He, L. et al. Spatial separation of charge carriers in In2O3−x(OH)y nanocrystal superstructures for enhanced gas-phase photocatalytic activity. ACS Nano 10, 5578–5586 (2016).

    CAS  Article  Google Scholar 

  31. 31.

    Zhao, H., Yin, W., Zhao, M., Song, Y. & Yang, H. Hydrothermal fabrication and enhanced photocatalytic activity of hexagram shaped InOOH nanostructures with exposed {020} facets. Appl. Catal. B 130–131, 178–186 (2013).

    Article  CAS  Google Scholar 

  32. 32.

    Gurlo, A. et al. Pressure-induced decomposition of indium hydroxide. J. Am. Chem. Soc. 132, 12674–12678 (2010).

    CAS  Article  Google Scholar 

  33. 33.

    Tang, Q. et al. Size-controllable growth of single crystal In(OH)3 and In2O3 nanocubes. Cryst. Growth Des. 5, 147–150 (2005).

    CAS  Article  Google Scholar 

  34. 34.

    Bondue, C. J., Graf, M., Goyal, A. & Koper, M. T. M. Suppression of hydrogen evolution in acidic electrolytes by electrochemical CO2 reduction. J. Am. Chem. Soc. 143, 279–285 (2021).

    CAS  Article  Google Scholar 

  35. 35.

    He, Y. et al. Self-gating in semiconductor electrocatalysis. Nat. Mater. 18, 1098–1104 (2019).

    CAS  Article  Google Scholar 

  36. 36.

    Lv, C. et al. An amorphous noble-metal-free electrocatalyst that enables nitrogen fixation under ambient conditions. Angew. Chem. Int. Ed. 57, 6073–6076 (2018).

    CAS  Article  Google Scholar 

  37. 37.

    Xu, L. et al. NOx sensitivity of conductometric In(OH)3 sensors operated at room temperature and transition from p- to n-type conduction. Sens. Actuators B 245, 533–540 (2017).

    CAS  Article  Google Scholar 

  38. 38.

    Niu, T. et al. D-A-p-A-D-type dopant-free hole transport material for low-cost, efficient, and stable perovskite solar cells. Joule 5, 249–269 (2021).

    CAS  Article  Google Scholar 

  39. 39.

    Takata, T. et al. Photocatalytic water splitting with a quantum efficiency of almost unity. Nature 581, 411–414 (2020).

    CAS  Article  Google Scholar 

  40. 40.

    Yu, J., Low, J., Xiao, W., Zhou, P. & Jaroniec, M. Enhanced photocatalytic CO2-reduction activity of anatase TiO2 by coexposed {001} and {101} facets. J. Am. Chem. Soc. 136, 8839–8842 (2014).

    CAS  Article  Google Scholar 

  41. 41.

    Yue, D., Jia, Y., Yao, J., Sun, J. & Jing, Y. Structure and electrochemical behavior of ionic liquid analogue based on choline chloride and urea. Electrochim. Acta 65, 30–36 (2012).

    CAS  Article  Google Scholar 

  42. 42.

    Keuleers, R., Desseyn, H. O., Rousseau, B. & Van Alsenoy, C. Vibrational analysis of urea. J. Phys. Chem. A 103, 4621–4630 (1999).

    CAS  Article  Google Scholar 

  43. 43.

    Yao, Y., Zhu, S., Wang, H., Li, H. & Shao, M. A spectroscopic study on the nitrogen electrochemical reduction reaction on gold and platinum surfaces. J. Am. Chem. Soc. 140, 1496–1501 (2018).

    CAS  Article  Google Scholar 

  44. 44.

    Manivannan, M. & Rajendran, S. Investigation of inhibitive action of urea-Zn2+ system in the corrosion control of carbon steel in sea water. Int. J. Eng. Sci. Technol. 3, 8048–8060 (2011).

    Google Scholar 

  45. 45.

    Nakamoto, K. in Handbook of Vibrational Spectroscopy Vol. 3 (eds Chalmers, J. M. & Griffiths, P.) 1872–1892 (Wiley, 2006).

  46. 46.

    Moysiadou, A., Lee, S., Hsu, C. S., Chen, H. M. & Hu, X. Mechanism of oxygen evolution catalyzed by cobalt oxyhydroxide: cobalt superoxide species as a key intermediate and dioxygen release as a rate-determining step. J. Am. Chem. Soc. 142, 11901–11914 (2020).

    CAS  Article  Google Scholar 

  47. 47.

    Rahmatullah, M. & Boyde, T. R. C. Improvements in the determination of urea using diacetyl monoxime; methods with and without deproteinisation. Clin. Chim. Acta 107, 3–9 (1980).

    CAS  Article  Google Scholar 

  48. 48.

    Zhao, Y. et al. Ammonia detection methods in photocatalytic and electrocatalytic experiments: how to improve the reliability of NH3 production rates? Adv. Sci. 6, 1802109 (2019).

    Article  CAS  Google Scholar 

  49. 49.

    Watt, G. W. & Chrisp, J. D. A spectrophotometric method for determination of hydrazine. Anal. Chem. 24, 2006–2008 (1952).

    CAS  Google Scholar 

  50. 50.

    Blochl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994).

    CAS  Article  Google Scholar 

  51. 51.

    Kresse, G. & Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 6, 15–50 (1996).

    CAS  Article  Google Scholar 

  52. 52.

    Kresse, G. & Furthmuller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).

    CAS  Article  Google Scholar 

  53. 53.

    Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

    CAS  Article  Google Scholar 

  54. 54.

    Monkhorst, H. J. & Pack, J. D. Special points for Brillouin-zone integrations. Phys. Rev. B 13, 5188–5192 (1976).

    Article  Google Scholar 

  55. 55.

    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  CAS  Google Scholar 

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Q.Y. acknowledges funding support from Singapore MOE AcRF Tier 1 grant no. 2020-T1-001-031, Tier 2 grant no. 2017-T2-2-069 and Singapore A*STAR project A19D9a0096. G.Y. acknowledges funding support from the US Department of Energy (grant number: DE-SC0019019) and Welch Foundation Award F-1861. S.L. acknowledges financial support from the Academic Research Fund Tier 1 (RG8/20), Tier 1 (RG104/18) and computing resources from the National Supercomputing Centre Singapore. This work is also supported by the Users with Excellence programme of Hefei Science Center of CAS(2020HSC-UE003). We greatly thank the Facility for Analysis, Characterization, Testing and Simulation (FACTS) of Nanyang Technological University, Singapore, for using their TEM, SEM and XRD equipment. We acknowledge NTU Center of High Field NMR Spectroscopy and Imaging. We also thank the National Synchrotron Radiation Laboratory for help in characterizations.

Author information




G.Y. and Q.Y. conceived and directed the project. C. Lv carried out key experiments and wrote the manuscript. L.Z. and S.L. performed theoretical calculations. H.L. and L.S. conducted operando SR-FTIR measurements. C.Y. carried out the design of catalysts. M.C., Y.K., J.L., C. Lee and D.L. conducted part of the characterizations. C. Lv, L.Z., Z.F., Q.Y., G.Y., G.C., L.S. and S.L. analysed the data. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Shuzhou Li or Li Song or Qingyu Yan or Guihua Yu.

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The authors declare no competing interests.

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Peer review information Nature Sustainability thanks Qi Shao and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Information

Supplementary Figs. 1–67, Discussion, Table 1 and references.

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Lv, C., Zhong, L., Liu, H. et al. Selective electrocatalytic synthesis of urea with nitrate and carbon dioxide. Nat Sustain (2021).

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