Abstract
The efficient reduction of atmospheric nitrogen to ammonia under low pressure and temperature conditions has been a challenge in meeting the rapidly increasing demand for fertilizers and hydrogen storage. Here, we report that Ca2N:e-, a two-dimensional electride, combined with ruthenium nanoparticles (Ru/Ca2N:e-) exhibits efficient and stable catalytic activity down to 200 °C. This catalytic performance is due to [Ca2N]+·e1-x-Hx- formed by a reversible reaction of an anionic electron with hydrogen (Ca2N:e- + xH ↔ [Ca2N]+·e1-x-Hx-) during ammonia synthesis. The simplest hydride, CaH2, with Ru also exhibits catalytic performance comparable to Ru/Ca2N:e-. The resultant electrons in these hydrides have a low work function of 2.3 eV, which facilitates the cleavage of N2 molecules. The smooth reversible exchangeability between anionic electrons and H- ions in hydrides at low temperatures suppresses hydrogen poisoning of the Ru surfaces. The present work demonstrates the high potential of metal hydrides as efficient promoters for low-temperature ammonia synthesis.
| Original language | English |
|---|---|
| Pages (from-to) | 4036-4043 |
| Number of pages | 8 |
| Journal | Chemical Science |
| Volume | 7 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - Jan 1 2016 |
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All Science Journal Classification (ASJC) codes
- Chemistry(all)
Cite this
Essential role of hydride ion in ruthenium-based ammonia synthesis catalysts. / Kitano, Masaaki; Inoue, Yasunori; Ishikawa, Hiroki; Yamagata, Kyosuke; Nakao, Takuya; Tada, Tomofumi; Matsuishi, Satoru; Yokoyama, Toshiharu; Hara, Michikazu; Hosono, Hideo.
In: Chemical Science, Vol. 7, No. 7, 01.01.2016, p. 4036-4043.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Essential role of hydride ion in ruthenium-based ammonia synthesis catalysts
AU - Kitano, Masaaki
AU - Inoue, Yasunori
AU - Ishikawa, Hiroki
AU - Yamagata, Kyosuke
AU - Nakao, Takuya
AU - Tada, Tomofumi
AU - Matsuishi, Satoru
AU - Yokoyama, Toshiharu
AU - Hara, Michikazu
AU - Hosono, Hideo
PY - 2016/1/1
Y1 - 2016/1/1
N2 - The efficient reduction of atmospheric nitrogen to ammonia under low pressure and temperature conditions has been a challenge in meeting the rapidly increasing demand for fertilizers and hydrogen storage. Here, we report that Ca2N:e-, a two-dimensional electride, combined with ruthenium nanoparticles (Ru/Ca2N:e-) exhibits efficient and stable catalytic activity down to 200 °C. This catalytic performance is due to [Ca2N]+·e1-x-Hx- formed by a reversible reaction of an anionic electron with hydrogen (Ca2N:e- + xH ↔ [Ca2N]+·e1-x-Hx-) during ammonia synthesis. The simplest hydride, CaH2, with Ru also exhibits catalytic performance comparable to Ru/Ca2N:e-. The resultant electrons in these hydrides have a low work function of 2.3 eV, which facilitates the cleavage of N2 molecules. The smooth reversible exchangeability between anionic electrons and H- ions in hydrides at low temperatures suppresses hydrogen poisoning of the Ru surfaces. The present work demonstrates the high potential of metal hydrides as efficient promoters for low-temperature ammonia synthesis.
AB - The efficient reduction of atmospheric nitrogen to ammonia under low pressure and temperature conditions has been a challenge in meeting the rapidly increasing demand for fertilizers and hydrogen storage. Here, we report that Ca2N:e-, a two-dimensional electride, combined with ruthenium nanoparticles (Ru/Ca2N:e-) exhibits efficient and stable catalytic activity down to 200 °C. This catalytic performance is due to [Ca2N]+·e1-x-Hx- formed by a reversible reaction of an anionic electron with hydrogen (Ca2N:e- + xH ↔ [Ca2N]+·e1-x-Hx-) during ammonia synthesis. The simplest hydride, CaH2, with Ru also exhibits catalytic performance comparable to Ru/Ca2N:e-. The resultant electrons in these hydrides have a low work function of 2.3 eV, which facilitates the cleavage of N2 molecules. The smooth reversible exchangeability between anionic electrons and H- ions in hydrides at low temperatures suppresses hydrogen poisoning of the Ru surfaces. The present work demonstrates the high potential of metal hydrides as efficient promoters for low-temperature ammonia synthesis.
UR - http://www.scopus.com/inward/record.url?scp=84976423734&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84976423734&partnerID=8YFLogxK
U2 - 10.1039/c6sc00767h
DO - 10.1039/c6sc00767h
M3 - Article
AN - SCOPUS:84976423734
VL - 7
SP - 4036
EP - 4043
JO - Chemical Science
JF - Chemical Science
SN - 2041-6520
IS - 7
ER -