TY - JOUR
T1 - Large Oblate Hemispheroidal Ruthenium Particles Supported on Calcium Amide as Efficient Catalysts for Ammonia Decomposition
AU - Kishida, Kazuhisa
AU - Kitano, Masaaki
AU - Inoue, Yasunori
AU - Sasase, Masato
AU - Nakao, Takuya
AU - Tada, Tomofumi
AU - Abe, Hitoshi
AU - Niwa, Yasuhiro
AU - Yokoyama, Toshiharu
AU - Hara, Michikazu
AU - Hosono, Hideo
PY - 2018/6/4
Y1 - 2018/6/4
N2 - Ammonia decomposition is an important technology for extracting hydrogen from ammonia toward the realization of a hydrogen economy. Herein, it is reported that large oblate hemispheroidal Ru particles on Ca(NH2)2 function as efficient catalysts for ammonia decomposition. The turnover frequency of Ru/Ca(NH2)2 increased by two orders of magnitude when the Ru particle size was increased from 1.5 to 8.4 nm. More than 90 % ammonia decomposition was achieved over Ru/Ca(NH2)2 with large oblate hemispheroidal Ru particles at 360 °C, which is comparable to that of alkali-promoted Ru catalysts with small Ru particle sizes. XAFS analyses revealed that Ru particles are immobilized on Ca(NH2)2 by Ru−N bonds formed at the metal/support interface, which lead to oblate hemispheroidal Ru particles. Such a strong metal–support interaction in Ru/Ca(NH2)2 is also substantiated by DFT calculations. The high activity of Ru/Ca(NH2)2 with large Ru particles primarily originates from the shape and appropriate size of the Ru particles with a high density of active sites rather than the electron-donating ability of Ca(NH2)2.
AB - Ammonia decomposition is an important technology for extracting hydrogen from ammonia toward the realization of a hydrogen economy. Herein, it is reported that large oblate hemispheroidal Ru particles on Ca(NH2)2 function as efficient catalysts for ammonia decomposition. The turnover frequency of Ru/Ca(NH2)2 increased by two orders of magnitude when the Ru particle size was increased from 1.5 to 8.4 nm. More than 90 % ammonia decomposition was achieved over Ru/Ca(NH2)2 with large oblate hemispheroidal Ru particles at 360 °C, which is comparable to that of alkali-promoted Ru catalysts with small Ru particle sizes. XAFS analyses revealed that Ru particles are immobilized on Ca(NH2)2 by Ru−N bonds formed at the metal/support interface, which lead to oblate hemispheroidal Ru particles. Such a strong metal–support interaction in Ru/Ca(NH2)2 is also substantiated by DFT calculations. The high activity of Ru/Ca(NH2)2 with large Ru particles primarily originates from the shape and appropriate size of the Ru particles with a high density of active sites rather than the electron-donating ability of Ca(NH2)2.
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U2 - 10.1002/chem.201800467
DO - 10.1002/chem.201800467
M3 - Article
C2 - 29603479
AN - SCOPUS:85046547607
VL - 24
SP - 7976
EP - 7984
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 31
ER -