TY - JOUR
T1 - High Electron Density on Ru in Intermetallic YRu2
T2 - The Application to Catalyst for Ammonia Synthesis
AU - Ogawa, Takaya
AU - Kobayashi, Yasukazu
AU - Mizoguchi, Hiroshi
AU - Kitano, Masaaki
AU - Abe, Hitoshi
AU - Tada, Tomofumi
AU - Toda, Yoshitake
AU - Niwa, Yasuhiro
AU - Hosono, Hideo
N1 - Funding Information:
This work was supported by funds from the Accelerated Innovation Research Initiative Turning Top Science and Ideas into High-Impact Values (ACCEL) program of the Japan Science and Technology Agency (JST). A portion of this work was supported by a Kakenhi Grant-in-Aid (No. 15H04183 & 17H06153) from the Japan Society for the Promotion of Science (JSPS). This work was supported by a JSPS postdoctoral fellowship for T.O. XAFS measurements were performed under the approval of PF−PAC No. 2013S2-002. The authors acknowledge Soshi Iimura for assistance with the Rietveld analysis and Toshiharu Yokoyama for valuable comments. We also thank Associate Professor Hiroyuki Wada for the cooperation in laser ablation experiments to obtain YRu2nanoparticles.
Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/5/17
Y1 - 2018/5/17
N2 - Ruthenium is the most effective catalyst reported to date for ammonia synthesis under mild conditions, especially when an electron promoter is used. However, electron donation from the promoter has not been sufficient because the promoter contacts with Ru only through its surface. Here, we report a Laves phase intermetallic bulk catalyst, YRu2, which has higher electron density on Ru. This is derived from large electron transfer from Y to Ru, which is first confirmed by X-ray absorption fine structure measurements and theoretical calculations. In addition, YRu2 has high hydrogen solubilities leading to suppression of hydrogen poisoning, a common drawback of Ru-based catalysts. Consequently, YRu2 exhibits higher catalytic activity for ammonia synthesis over 300 times that with pure ruthenium. The present results suggest a simple concept for ammonia synthesis: Laves phase intermetallic compounds of Ru and more electropositive metals are more efficient catalysts than pure Ru because of the large electron promotion and suppression of hydrogen poisoning.
AB - Ruthenium is the most effective catalyst reported to date for ammonia synthesis under mild conditions, especially when an electron promoter is used. However, electron donation from the promoter has not been sufficient because the promoter contacts with Ru only through its surface. Here, we report a Laves phase intermetallic bulk catalyst, YRu2, which has higher electron density on Ru. This is derived from large electron transfer from Y to Ru, which is first confirmed by X-ray absorption fine structure measurements and theoretical calculations. In addition, YRu2 has high hydrogen solubilities leading to suppression of hydrogen poisoning, a common drawback of Ru-based catalysts. Consequently, YRu2 exhibits higher catalytic activity for ammonia synthesis over 300 times that with pure ruthenium. The present results suggest a simple concept for ammonia synthesis: Laves phase intermetallic compounds of Ru and more electropositive metals are more efficient catalysts than pure Ru because of the large electron promotion and suppression of hydrogen poisoning.
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U2 - 10.1021/acs.jpcc.8b02128
DO - 10.1021/acs.jpcc.8b02128
M3 - Article
AN - SCOPUS:85047543334
VL - 122
SP - 10468
EP - 10475
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 19
ER -