Abstract
Due to the high energy needed to break the N ≡ N bond (945 kJ mol−1), a key step in ammonia production is the activation of dinitrogen, which in industry requires the use of transition metal catalysts such as iron (Fe) or ruthenium (Ru), in combination with high temperatures and pressures. Here we demonstrate a transition-metal-free catalyst—potassium hydride-intercalated graphite (KH0.19C24)—that can activate dinitrogen at very moderate temperatures and pressures. The catalyst catalyses NH3 synthesis at atmospheric pressure and achieves NH3 productivity (µmolNH3 gcat−1 h−1) comparable to the classical noble metal catalyst Ru/MgO at temperatures of 250–400 °C and 1 MPa. Both experimental and computational calculation results demonstrate that nanoconfinement of potassium hydride between the graphene layers is crucial for the activation and conversion of dinitrogen. Hydride in the catalyst participates in the hydrogenation step to form NH3. This work shows the promise of light metal hydride materials in the catalysis of ammonia synthesis. [Figure not available: see fulltext.].
| Original language | English |
|---|---|
| Pages (from-to) | 222-230 |
| Number of pages | 9 |
| Journal | Nature Catalysis |
| Volume | 5 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 17 Mar 2022 |
Bibliographical note
Funding Information:We thank S. Zanoni for N physisorption measurements, and Netherlands Organisation for Scientific Research (NWO)-Vici (no. 16.130.344) for overall funding of the project. P.N. and P.E.d.J. acknowledge support from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (ERC-2014-CoG, no. 648991). S.E. acknowledges funding from the initiative ‘Computational Sciences for Energy Research’ from Shell and NWO grant no. 15CSTT05. The computational part of this work was sponsored by NWO Exact and Natural Sciences for the use of supercomputer facilities. We thank P. Chen and J. Guo for useful discussions. 2
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Nature Limited.
Funding
We thank S. Zanoni for N physisorption measurements, and Netherlands Organisation for Scientific Research (NWO)-Vici (no. 16.130.344) for overall funding of the project. P.N. and P.E.d.J. acknowledge support from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (ERC-2014-CoG, no. 648991). S.E. acknowledges funding from the initiative ‘Computational Sciences for Energy Research’ from Shell and NWO grant no. 15CSTT05. The computational part of this work was sponsored by NWO Exact and Natural Sciences for the use of supercomputer facilities. We thank P. Chen and J. Guo for useful discussions. 2