Graphene-induced growth of N-doped niobium pentaoxide nanorods with high catalytic activity for hydrogen storage in MgH2

Ke Wang, Xin Zhang, Yongfeng Liu, Zhuanghe Ren, Xuelian Zhang, Jianjiang Hu, Mingxia Gao, Hongge Pan

Research output: Contribution to journalArticlepeer-review

149 Scopus citations

Abstract

High operation temperatures and slow kinetics remain big challenges for using magnesium (Mg) as a practical hydrogen storage medium. In this work, a novel graphene-guided nucleation and growth process was developed for the preparation of N-doped Nb2O5 nanorods that enable remarkably improved hydrogen storage properties of MgH2. The nanorods were measured to be 10–20 nm in diameter. MgH2 doped with 10 wt% of the nanorods released 6.2 wt% H2 from 170 °C, which is 130 °C lower than additive-free MgH2, thanks to a 40% reduction in the kinetic barriers. About 5.5 wt% of H2 was desorbed in isothermal dehydrogenation test at 175 °C. Reloading of hydrogen was notably completed at 25 °C under 50 atm of hydrogen pressure, which has not been reported before. Density functional theory (DFT) calculations demonstrate the extended bond lengths and weakened bond strengths of Mg-H or H-H when MgH2/H2 adsorbs on the Nb-N-O/graphene model, consequently favouring lower operating temperatures and improved kinetics for hydrogen storage in MgH2 catalyzed by the graphene-guided N-Nb2O5 nanorods. Our findings provide useful insights in the design and preparation of high-performance catalysts of transition metals and rare metals for on-board hydrogen storage.

Original languageEnglish
Article number126831
JournalChemical Engineering Journal
Volume406
DOIs
StatePublished - 15 Feb 2021
Externally publishedYes

Keywords

  • Graphene
  • Hydriding
  • Hydrogen storage
  • Magnesium hydride
  • Transition metal catalysts

Fingerprint

Dive into the research topics of 'Graphene-induced growth of N-doped niobium pentaoxide nanorods with high catalytic activity for hydrogen storage in MgH2'. Together they form a unique fingerprint.

Cite this