Ammonia synthesis using a stable electride as an electron donor and reversible hydrogen store

ABSTRACT Industrially, the artificial fixation of atmospheric nitrogen to ammonia is carried out using the Haber–Bosch process, but this process requires high temperatures and pressures, and

consumes more than 1% of the world's power production. Therefore the search is on for a more environmentally benign process that occurs under milder conditions. Here, we report that a

Ru-loaded electride [Ca24Al28O64]4+(e−)4 (Ru/C12A7:e−), which has high electron-donating power and chemical stability, works as an efficient catalyst for ammonia synthesis. Highly efficient

ammonia synthesis is achieved with a catalytic activity that is an order of magnitude greater than those of other previously reported Ru-loaded catalysts and with almost half the reaction

activation energy. Kinetic analysis with infrared spectroscopy reveals that C12A7:e− markedly enhances N2 dissociation on Ru by the back donation of electrons and that the poisoning of

ruthenium surfaces by hydrogen adatoms can be suppressed effectively because of the ability of C12A7:e− to store hydrogen reversibly. Access through your institution Buy or subscribe This is

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iron–cobalt alloys supported on carbon. _J. Catal._ 214, 327–335 (2003). Article  CAS  Google Scholar  Download references ACKNOWLEDGEMENTS We deeply appreciate K. Aika for his suggestions.

Discussions with K. Nakajima and Y. Toda are acknowledged. We thank T. Yoshizumi, S. Nakamura and D. Lu for their technical assistance. This work was supported by a Funding Program for

World-Leading Innovative R&D on Science and Technology from the Japan Society for the Promotion of Science. A part of this work was supported by a fund from the Element Strategy

Initiative Project of the Ministry of Education, Culture, Sports and Science for Technology in Japan. AUTHOR INFORMATION Author notes * Sung-Wng Kim Present address: Present address:

Department of Energy Science, SungKyunKwan University, Suwon, Korea, AUTHORS AND AFFILIATIONS * Materials and Structures Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku,

226-8503, Yokohama, Japan Masaaki Kitano, Yasunori Inoue, Youhei Yamazaki, Shinji Kanbara, Michikazu Hara & Hideo Hosono * Frontier Research Center, Tokyo Institute of Technology, 4259

Nagatsuta, Midori-ku, 226-8503, Yokohama, Japan Fumitaka Hayashi, Satoru Matsuishi, Toshiharu Yokoyama, Sung-Wng Kim & Hideo Hosono Authors * Masaaki Kitano View author publications You

can also search for this author inPubMed Google Scholar * Yasunori Inoue View author publications You can also search for this author inPubMed Google Scholar * Youhei Yamazaki View author

publications You can also search for this author inPubMed Google Scholar * Fumitaka Hayashi View author publications You can also search for this author inPubMed Google Scholar * Shinji

Kanbara View author publications You can also search for this author inPubMed Google Scholar * Satoru Matsuishi View author publications You can also search for this author inPubMed Google

Scholar * Toshiharu Yokoyama View author publications You can also search for this author inPubMed Google Scholar * Sung-Wng Kim View author publications You can also search for this author

inPubMed Google Scholar * Michikazu Hara View author publications You can also search for this author inPubMed Google Scholar * Hideo Hosono View author publications You can also search for

this author inPubMed Google Scholar CONTRIBUTIONS H.H. proposed the idea behind this research and M.H. and H.H. directed the entire project. M.K., Y.I., Y.Y., F.H., S.M., S.K., T.Y. and

S-W.K. performed the synthesis, characterization and catalytic testing of Ru/C12A7:e−. All the authors discussed the results and commented on the study. M.K., M.H. and H.H. co-wrote the

manuscript. CORRESPONDING AUTHORS Correspondence to Michikazu Hara or Hideo Hosono. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing financial interests.

SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION Supplementary information (PDF 809 kb) RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Kitano, M.,

Inoue, Y., Yamazaki, Y. _et al._ Ammonia synthesis using a stable electride as an electron donor and reversible hydrogen store. _Nature Chem_ 4, 934–940 (2012).

https://doi.org/10.1038/nchem.1476 Download citation * Received: 24 May 2012 * Accepted: 06 September 2012 * Published: 21 October 2012 * Issue Date: November 2012 * DOI:

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