TY - JOUR
T1 - Structural and catalytic properties of supported Ni-Ir alloy catalysts for H2 generation via hydrous hydrazine decomposition
AU - He, Lei
AU - Huang, Yanqiang
AU - Liu, Xiao Yan
AU - Li, Lin
AU - Wang, Aiqin
AU - Wang, Xiaodong
AU - Mou, Chung Yuan
AU - Zhang, Tao
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China ( 21103173 , 21173218 ) and the “Hundred Talents Program of Dalian Institute of Chemical Physics” . We also acknowledge the Shanghai Synchrotron Radiation Facility (SSRF) and the National Synchrotron Radiation Research Center of Taiwan (NSRRC) for the XAS experiment.
PY - 2014/4/5
Y1 - 2014/4/5
N2 - Iridium modified Ni/Al2O3 catalysts were prepared using Ni-Al hydrotalcite as precursor and tested in the selective decomposition of hydrous hydrazine for H2 generation. Compared to Ni/Al2O3, NiIrx/Al2O3 catalysts exhibited an increase of the reaction rate up to 6-fold and the H2 selectivity from 93% to above 99%. The XRD and EXAFS analysis confirmed that Ir and Ni were present in the form of Ni-Ir alloy; and the H2 differential heat of adsorption is appreciably lowered with increasing the amount of Ir in Ni-Ir alloy. High-temperature reduction, e.g. 700°C, induced the migration of Ir atoms into the Ni bulk and produced a Ni-skin surface. This structural modification is associated with a strongly decrease of activity and selectivity. EXAFS measurements were also performed on different noble metals (NM, Ir, Pt, and Au) modified Ni/Al2O3 catalysts in order to verify the extent of NM-Ni bimetallic bond formation, which was found to correlate with the catalytic performance.
AB - Iridium modified Ni/Al2O3 catalysts were prepared using Ni-Al hydrotalcite as precursor and tested in the selective decomposition of hydrous hydrazine for H2 generation. Compared to Ni/Al2O3, NiIrx/Al2O3 catalysts exhibited an increase of the reaction rate up to 6-fold and the H2 selectivity from 93% to above 99%. The XRD and EXAFS analysis confirmed that Ir and Ni were present in the form of Ni-Ir alloy; and the H2 differential heat of adsorption is appreciably lowered with increasing the amount of Ir in Ni-Ir alloy. High-temperature reduction, e.g. 700°C, induced the migration of Ir atoms into the Ni bulk and produced a Ni-skin surface. This structural modification is associated with a strongly decrease of activity and selectivity. EXAFS measurements were also performed on different noble metals (NM, Ir, Pt, and Au) modified Ni/Al2O3 catalysts in order to verify the extent of NM-Ni bimetallic bond formation, which was found to correlate with the catalytic performance.
KW - EXAFS
KW - Hydrazine
KW - Hydrogen storage
KW - Microcalorimeter
KW - Nickel-iridium alloy
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U2 - 10.1016/j.apcatb.2013.10.022
DO - 10.1016/j.apcatb.2013.10.022
M3 - Article
AN - SCOPUS:84887012960
SN - 0926-3373
VL - 147
SP - 779
EP - 788
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
ER -