Abstract
Ammonia synthesis under mild conditions is a goal that has been long sought after. Previous investigations have shown that adsorption and transition-state energies of intermediates in this process on transition metals (TMs) scale with each other. This prevents the independent optimization of these energies that would result in the ideal catalyst: one that activates reactants well, but binds intermediates relatively weakly. Here we demonstrate that these scaling relations can be broken by intervening in the TM-mediated catalysis with a second catalytic site, LiH. The negatively charged hydrogen atoms of LiH act as strong reducing agents, which remove activated nitrogen atoms from the TM or its nitride (TMN), and as an immediate source of hydrogen, which binds nitrogen atoms to form LiNH2. LiNH2 further splits H2 heterolytically to give off NH3 and regenerate LiH. This synergy between TM (or TMN) and LiH creates a favourable pathway that allows both early and late 3d TM–LiH composites to exhibit unprecedented lower-temperature catalytic activities.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Erisman, J. W., Sutton, M. A., Galloway, J., Klimont, Z. & Winiwarter, W. How a century of ammonia synthesis changed the world. Nat. Geosci. 1, 636–639 (2008).
Burgess, B. K. & Lowe, D. J. Mechanism of molybdenum nitrogenase. Chem. Rev. 96, 2983–3011 (1996).
Schlögl, R. Catalytic synthesis of ammonia—a ‘never-ending story’? Angew. Chem. Int. Ed. 42, 2004–2008 (2003).
Kojima, R. & Aika, K. Cobalt molybdenum bimetallic nitride catalysts for ammonia synthesis. Chem. Lett. 29, 514–515 (2000).
Jacobsen, C. J. H. et al. Catalyst design by interpolation in the periodic table: bimetallic ammonia synthesis catalysts. J. Am. Chem. Soc. 123, 8404–8405 (2001).
Kitano, M. et al. Ammonia synthesis using a stable electride as an electron donor and reversible hydrogen store. Nat. Chem. 4, 934–940 (2012).
Zhu, D., Zhang, L. H., Ruther, R. E. & Hamers, R. J. Photo-illuminated diamond as a solid-state source of solvated electrons in water for nitrogen reduction. Nature Mater. 12, 836–841 (2013).
Licht, S. et al. Ammonia synthesis by N2 and steam electrolysis in molten hydroxide suspensions of nanoscale Fe2O3 . Science 345, 637–640 (2014).
Yandulov, D. V. & Schrock, R. R. Catalytic reduction of dinitrogen to ammonia at a single molybdenum center. Science 301, 76–78 (2003).
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).
Anderson, J. S., Rittle, J. & Peters, J. C. Catalytic conversion of nitrogen to ammonia by an iron model complex. Nature 501, 84–88 (2013).
Montemore, M. M. & Medlin, J. W. Scaling relations between adsorption energies for computational screening and design of catalysts. Catal. Sci. Technol. 4, 3748–3761 (2014).
Pallassana, V. & Neurock, M. Electronic factors governing ethylene hydrogenation and dehydrogenation activity of pseudomorphic Pd–ML/Re(0001), Pd–ML/Ru(0001), Pd(111), and Pd–ML/Au(111) surfaces. J. Catal. 191, 301–317 (2000).
Abild-Pedersen, F. et al. Scaling properties of adsorption energies for hydrogen-containing molecules on transition-metal surfaces. Phys. Rev. Lett. 99, 016105 (2007).
Calle-Vallejo, F., Loffreda, D., Koper, M. T. M. & Sautet, P. Introducing structural sensitivity into adsorption-energy scaling relations by means of coordination numbers. Nat. Chem. 7, 403–410 (2015).
Nørskov, J. K., Bligaard, T., Rossmeisl, J. & Christensen, C. H. Towards the computational design of solid catalysts. Nat. Chem. 1, 37–46 (2009).
Chen, Y., Salciccioli, M. & Vlachos, D. G. An efficient reaction pathway search method applied to the decomposition of glycerol on platinum. J. Phys. Chem. C 115, 18707–18720 (2011).
Medford, A. J. et al. From the Sabatier principle to a predictive theory of transition-metal heterogeneous catalysis. J. Catal. 328, 36–42 (2015).
Vojvodic, A. et al. Exploring the limits: a low-pressure, low-temperature Haber–Bosch process. Chem. Phys. Lett. 598, 108–112 (2014).
Akagi, F., Matsuo, T. & Kawaguchi, H. Dinitrogen cleavage by a diniobium tetrahydride complex: formation of a nitride and its conversion into imide species. Angew. Chem. Int. Ed. 46, 8778–8781 (2007).
Avenier, P. et al. Dinitrogen dissociation on an isolated surface tantalum atom. Science 317, 1056–1060 (2007).
Shima, T. et al. Dinitrogen cleavage and hydrogenation by a trinuclear titanium polyhydride complex. Science 340, 1549–1552 (2013).
Pfirrmann, S., Limberg, C., Herwig, C., Stosser, R. & Ziemer, B. A dinuclear nickel(I) dinitrogen complex and its reduction in single-electron steps. Angew. Chem. Int. Ed. 48, 3357–3361 (2009).
King, D. A. & Sebba, F. Catalytic synthesis of ammonia over vanadium nitride containing oxygen. 1. The reaction mechanism. J. Catal. 4, 253–259 (1965).
Mittasch, A. Early studies of multicomponent catalysts. Adv. Catal. 2, 81–104 (1950).
Ertl, G. Surface science and catalysis—studies on the mechanism of ammonia synthesis: the P. H. Emmett award address. Catal. Rev. Sci. Eng. 21, 201–223 (1980).
Fernandez, E. M. et al. Scaling relationships for adsorption energies on transition metal oxide, sulfide, and nitride surfaces. Angew. Chem. Int. Ed. 47, 4683–4686 (2008).
Scholten, J. J. F. & Zwietering, P. Kinetics of the chemisorption of nitrogen on ammonia-synthesis catalysts. Trans. Faraday Soc. 53, 1363–1370 (1957).
Stoltze, P. & Nørskov, J. K. Bridging the ‘pressure gap’ between ultrahigh-vacuum surface physics and high-pressure catalysis. Phys. Rev. Lett. 55, 2502–2505 (1985).
Chen, P., Xiong, Z. T., Luo, J. Z., Lin, J. Y. & Tan, K. L. Interaction of hydrogen with metal nitrides and imides. Nature 420, 302–304 (2002).
Leng, H. Y., Ichikawa, T., Hino, S. & Fujii, H. Investigation of reaction between LiNH2 and H2 . J. Alloys Compd 463, 462–465 (2008).
Goshome, K. et al. Ammonia synthesis via non-equilibrium reaction of lithium nitride in hydrogen flow condition. Mater. Trans. 56, 410–414 (2015).
Chen, P., Xiong, Z. T., Luo, J. Z., Lin, J. Y. & Tan, K. L. Interaction between lithium amide and lithium hydride. J. Phys. Chem. B 107, 10967–10970 (2003).
Tanabe, Y. & Nishibayashi, Y. Developing more sustainable processes for ammonia synthesis. Coord. Chem. Rev. 257, 2551–2564 (2013).
Schlögl, R. in Handbook of Heterogeneous Catalysis (eds Ertl, G., Knözinger, H., Schüth, F. & Weitkamp, J.) 2501–2575 (Wiley, 2008).
Hagen, S. et al. Ammonia synthesis with barium-promoted iron–cobalt alloys supported on carbon. J. Catal. 214, 327–335 (2003).
Rosowski, F. et al. Ruthenium catalysts for ammonia synthesis at high pressures: preparation, characterization, and power-law kinetics. Appl. Catal. A 151, 443–460 (1997).
Miyaoka, H. et al. Improvement of reaction kinetics by metal chloride on ammonia and lithium hydride system. Int. J. Hydrogen Energy 37, 16025–16030 (2012).
Kojima, R. & Aika, K. Cobalt molybdenum bimetallic nitride catalysts for ammonia synthesis. Part 2. Kinetic study. Appl. Catal. A 218, 121–128 (2001).
Fastrup, B., Muhler, M., Nielsen, H. N. & Nielsen, L. P. The interaction of H2 and N2 with iron catalysts used for NH3 synthesis—a temperature-programmed desorption and reaction study. J. Catal. 142, 135–146 (1993).
Chan, K., Tsai, C., Hansen, H. A. & Nørskov, J. K. Molybdenum sulfides and selenides as possible electrocatalysts for CO2 reduction. ChemCatChem 6, 1899–1905 (2014).
Koel, B. E. & Kim, J. in Handbook of Heterogeneous Catalysis (eds Ertl, G., Knözinger, H., Schüth, F. & Weitkamp, J.) 1593–1624 (Wiley, 2008).
Aika, K., Takano, T. & Murata, S. Preparation and characterization of chlorine-free ruthenium catalyst and the promoter effect in ammonia synthesis. 3. A magnesia-supported ruthenium catalyst. J. Catal. 136, 126–140 (1992).
Yin, S. F., Xu, B. Q., Zhou, X. P. & Au, C. T. A mini-review on ammonia decomposition catalysts for on-site generation of hydrogen for fuel cell applications. Appl. Catal. A 277, 1–9 (2004).
Guo, J. P. et al. Lithium imide synergizes with 3d transition metal nitrides leading to unprecedented catalytic activities. Angew. Chem. Int. Ed. 54, 2950–2954 (2015).
Hino, S., Ichikawa, T. & Kojima, Y. Thermodynamic properties of metal amides determined by ammonia pressure-composition isotherms. J. Chem. Thermodyn. 42, 140–143 (2010).
Binnewies, M. & Milke, E. Thermochemical Data of Elements and Compounds 2nd edn (Wiley, 2002).
Zhang, J. Studies on Thermodynamics and Kinetics of Ferromanganese Nitriding PhD thesis, Chongqing Univ. (2004).
Aika, K. & Tamaru, K. in Ammonia: Catalysis and Manufacture (ed. Nielsen, A.) 103–148 (Springer, 1995).
Imai, Y., Sohma, M. & Suemasu, T. Energetic stability and magnetic moment of tri-, tetra-, and octa-ferromagnetic element nitrides predicted by first-principle calculations. J. Alloys Compd 611, 440–445 (2014).
Acknowledgements
This work is dedicated to K. R. Tsai for his enlightenment and encouragement. The authors thank Z. Xiong for his earlier efforts in this study, and T. Zhang and X. Bao for beneficial discussions. The authors also thank the Dalian Institute of Chemical Physics (DICP DMTO201504), the Project of National Science Funds for Distinguished Young Scholars (51225206) and the Collaborative Innovation Center of Chemistry for Energy Materials (2011-iChEM) for financial support. We also thank the Shanghai Synchrotron Radiation Facility (BL14W1) for providing beam time.
Author information
Authors and Affiliations
Contributions
P.C. conceived the research and wrote the paper. J.G. coordinated the experimental work. P.W., F.C., W.G. and J.G. performed the synthesis, characterization and activity tests for the Fe–, Mn–, Co– and Cr–LiH catalysts, respectively. G.W. and T.H. helped with data analyses. P.W. and F.C. contributed equally to this work. All the authors discussed the results of the manuscript.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary information
Supplementary information (PDF 614 kb)
Rights and permissions
About this article
Cite this article
Wang, P., Chang, F., Gao, W. et al. Breaking scaling relations to achieve low-temperature ammonia synthesis through LiH-mediated nitrogen transfer and hydrogenation. Nature Chem 9, 64–70 (2017). https://doi.org/10.1038/nchem.2595
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nchem.2595
This article is cited by
-
Unusual Sabatier principle on high entropy alloy catalysts for hydrogen evolution reactions
Nature Communications (2024)
-
Anionic Defects Enhanced Ammonia Synthesis Over Ru Catalyst Supported on Barium Niobate Reduced with CaH2
Catalysis Letters (2024)
-
Efficient electrocatalytic reduction of nitrate to ammonia at low concentration by copper-cobalt oxide nanowires with shell–core structure
Nano Research (2024)
-
Order–disorder and ionic conductivity in calcium nitride-hydride
Nature Communications (2023)
-
Multiple reaction pathway on alkaline earth imide supported catalysts for efficient ammonia synthesis
Nature Communications (2023)