TY - JOUR
T1 - In situ formed ultrafine NbTi nanocrystals from a NbTiC solid-solution MXene for hydrogen storage in MgH2
AU - Wang, Zeyi
AU - Zhang, Xuelian
AU - Ren, Zhuanghe
AU - Liu, Yong
AU - Hu, Jianjiang
AU - Li, Haiwen
AU - Gao, Mingxia
AU - Pan, Hongge
AU - Liu, Yongfeng
N1 - Funding Information:
We gratefully acknowledge the nancial support received from the National Natural Science Foundation of China (51671172 and U1601212), the National Key R&D Program of China (2018YFB1502102) and the National Youth Top-Notch Talent Support Program.
Publisher Copyright:
© 2019 The Royal Society of Chemistry.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - A novel 2D layered NbTiC solid-solution MXene was synthesized from its MAX phase via a wet chemical etching process. While ball milling the NbTiC MXene with MgH2, ultrafine bimetal NbTi nanocrystals were formed in situ with a grain size of 5 nm, which offer highly stable catalytic activity for the hydrogen storage reaction of MgH2. The MgH2-9 wt% NbTiC sample starts releasing hydrogen from 195 °C, which is 80 °C lower than that for the additive-free sample. At 250 °C, it releases approximately 5.8 wt% H2 within 30 min, and the fully dehydrogenated sample takes up 4.0 wt% H2 within 15 min even at 50 °C under 50 bar H2 pressure. DFT calculations reveal a charge transfer process from Ti atoms to Nb atoms in the NbTi cluster and a lower absolute value of the adsorption energy of H2 on NbTi. This would presumably benefit both the breakage of Mg-H bonding and the detachment of H2 from the NbTi surface, and consequently lead to good catalytic activity.
AB - A novel 2D layered NbTiC solid-solution MXene was synthesized from its MAX phase via a wet chemical etching process. While ball milling the NbTiC MXene with MgH2, ultrafine bimetal NbTi nanocrystals were formed in situ with a grain size of 5 nm, which offer highly stable catalytic activity for the hydrogen storage reaction of MgH2. The MgH2-9 wt% NbTiC sample starts releasing hydrogen from 195 °C, which is 80 °C lower than that for the additive-free sample. At 250 °C, it releases approximately 5.8 wt% H2 within 30 min, and the fully dehydrogenated sample takes up 4.0 wt% H2 within 15 min even at 50 °C under 50 bar H2 pressure. DFT calculations reveal a charge transfer process from Ti atoms to Nb atoms in the NbTi cluster and a lower absolute value of the adsorption energy of H2 on NbTi. This would presumably benefit both the breakage of Mg-H bonding and the detachment of H2 from the NbTi surface, and consequently lead to good catalytic activity.
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U2 - 10.1039/c9ta03665b
DO - 10.1039/c9ta03665b
M3 - Article
AN - SCOPUS:85067233512
SN - 2050-7488
VL - 7
SP - 14244
EP - 14252
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 23
ER -
