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ZIF-67 derived Co@CNTs nanoparticles: Remarkably improved hydrogen storage properties of MgH 2 and synergetic catalysis mechanism

journal contribution
posted on 09.07.2019, 13:45 by Meijia Liu, Xuezhang Xiao, Shuchun Zhao, Sina Saremi-YarahmadiSina Saremi-Yarahmadi, Man Chen, Jiaguang Zheng, Shouquan Li, Lixin Chen
© 2018 Hydrogen Energy Publications LLC Transition-metal nanoparticles (NPs) can catalytically improve the hydrogen desorption/absorption kinetics of MgH 2 , yet this catalysis could be enhanced further by supporting NPs on carbon-based matrix materials. In this work, Co NPs with a uniform size of 10 nm loaded on carbon nanotubes (Co@CNTs) were synthesized in situ by carbonizing zeolitic imidazolate framework-67 (ZIF-67). The novel Co@CNTs nanocatalyst was subsequently doped into MgH 2 to remarkably improve its hydrogen storage properties. The MgH 2 -Co@CNTs starts to obviously release hydrogen at 267.8 °C, displaying complete release of hydrogen at the capacity of 6.89 wt% at 300 °C within 15 min. For absorption, the MgH 2 -Co@CNTs uptakes 6.15 wt% H 2 at 250 °C within 2 min. Moreover, both improved hydrogen capacity and enhanced reaction kinetics of MgH 2 -Co@CNTs can be well preserved during the 10 cycles, which confirms the excellent cycling hydrogen storage performances. Based on XRD, TEM and EDS results, the catalytic mechanism of MgH 2 -Co@CNTs can be ascribed to the synergetic effects of reversible phase transformation of Mg 2 Co to Mg 2 CoH 5 , and physical transformation of CNTs to carbon pieces. It is demonstrated that phase transformation of Mg 2 Co/Mg 2 CoH 5 can act as “hydrogen gateway” to catalytically accelerate the de/rehydrogenation kinetics of MgH 2 . Meanwhile, the carbon pieces coated on the surfaces of MgH 2 particles not only offer diffusion channels for hydrogen atoms but also prevent aggregation of MgH 2 NPs, resulting in the fast reaction rate and excellent cycling hydrogen storage properties of MgH 2 -Co@CNTs system.

Funding

The authors gratefully acknowledge the financial supports for this research from the National Natural Science Foundation of China (51571179 and 51671173), the Program for Innovative Research Team in University of Ministry of Education of China (IRT13037).

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Materials

Published in

International Journal of Hydrogen Energy

Volume

44

Issue

2

Pages

1059 - 1069

Citation

LIU, M. ... et al., 2019. ZIF-67 derived Co@CNTs nanoparticles: Remarkably improved hydrogen storage properties of MgH 2 and synergetic catalysis mechanism. International Journal of Hydrogen Energy, 44(2), pp. 1059 - 1069.

Publisher

© Hydrogen Energy Publications LLC. Published by Elsevier Ltd.

Version

SMUR (Submitted Manuscript Under Review)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2018-12-06

Notes

This paper is in closed access.

ISSN

0360-3199

Language

en