Issue 37, 2022

MgH2/single-atom heterojunctions: effective hydrogen storage materials with facile dehydrogenation

Abstract

Magnesium hydride (MgH2) is considered as a promising solid-state hydrogen storage material due to its high hydrogen storage mass density and environmental friendliness. However, its sluggish dehydrogenation kinetics are still the bottleneck that restricts practical applications. To address this challenge, very recent pioneering experiments found that MgH2/single-atom catalyst (MgH2/SAC) heterojunctions can be promising candidates for hydrogen storage. However, the reaction mechanism and design guideline were still not well understood. Herein, we design and analyze MgH2/SAC heterojunction systems including nine 3d transition metals, using spin-polarized density functional theory calculations with van der Waals corrections. We found that the energy barriers of MgH2 dehydrogenation are significantly reduced by 0.51–2.22 eV through the promotion effects of a heterojunction. Using ab initio molecular dynamics simulations, these promotion effects were analyzed in depth based on the observation of hydrogen diffusion behaviors. To provide further insights, the electron localization function, charge density difference, hydrogen adsorption energy, system electronegativity, d-band center, and crystal orbital Hamilton population were comprehensively analyzed to understand the origin of the high performance of MgH2/SACs. In particular, we found that the system electronegativity of SACs can act as an effective descriptor that predicts the dehydrogenation energy barriers. Most importantly, this study provides important design guidelines of a brand-new type of MgH2/SAC material and a promising solution to the sluggish kinetics of MgH2 dehydrogenation in hydrogen storage.

Graphical abstract: MgH2/single-atom heterojunctions: effective hydrogen storage materials with facile dehydrogenation

Supplementary files

Article information

Article type
Paper
Submitted
17 mar 2022
Accepted
09 mai 2022
First published
10 mai 2022

J. Mater. Chem. A, 2022,10, 19839-19851

MgH2/single-atom heterojunctions: effective hydrogen storage materials with facile dehydrogenation

S. Dong, C. Li, E. Lv, J. Wang, H. Liu, Z. Gao, W. Xiong, Z. Ding, W. Yang and H. Li, J. Mater. Chem. A, 2022, 10, 19839 DOI: 10.1039/D2TA02111K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements