eprintid: 10167826
rev_number: 7
eprint_status: archive
userid: 699
dir: disk0/10/16/78/26
datestamp: 2023-04-05 16:03:58
lastmod: 2023-04-05 16:03:58
status_changed: 2023-04-05 16:03:58
type: article
metadata_visibility: show
sword_depositor: 699
creators_name: Al-Hamdani, Yasmine S
creators_name: Zen, Andrea
creators_name: Michaelides, Angelos
creators_name: Alfè, Dario
title: Mechanisms of adsorbing hydrogen gas on metal decorated graphene
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
divisions: F57
divisions: F60
note: This is the published version of record. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: Hydrogen is a key player in global strategies to reduce greenhouse gas emissions. In order to make hydrogen
a widely used fuel, we require more efficient methods of storing it than the current standard of pressurized
cylinders. An alternative method is to adsorb H2 in a material and avoid the use of high pressures. Among many
potential materials, layered materials such as graphene present a practical advantage as they are lightweight.
However, graphene and other 2D materials typically bind H2 too weakly to store it at the typical operating
conditions of a hydrogen fuel cell, meaning that high pressure would still be required. Modifying the material,
for example by decorating graphene with adatoms, can strengthen the adsorption energy of H2 molecules, but
the underlying mechanisms are still not well understood. In this work, we systematically screen alkali and
alkaline-earth metal decorated graphene sheets for the static thermodynamic adsorption of hydrogen gas from
first principles and focus on the mechanisms of binding. We show that there are three mechanisms of adsorption
on metal decorated graphene and each leads to distinctly different hydrogen adsorption structures. The three
mechanisms can be described as weak van der Waals physisorption, metal adatom facilitated polarization, and
Kubas adsorption. Among these mechanisms, we find that Kubas adsorption is easily perturbed by an external
electric field, providing a way to tune H2 adsorption. This work is foundational and builds our understanding of
H2 adsorption under idealized conditions.
date: 2023-03
date_type: published
publisher: American Physical Society (APS)
official_url: https://doi.org/10.1103/PhysRevMaterials.7.035402
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
article_type_text: Article
verified: verified_manual
elements_id: 2014097
doi: 10.1103/physrevmaterials.7.035402
lyricists_name: Michaelides, Angelos
lyricists_name: Al-Hamdani, Yasmine
lyricists_name: Zen, Andrea
lyricists_name: Alfe, Dario
lyricists_id: AMICH30
lyricists_id: YSALH17
lyricists_id: AZENX51
lyricists_id: DALFE65
actors_name: Flynn, Bernadette
actors_id: BFFLY94
actors_role: owner
full_text_status: public
publication: Physical Review Materials
volume: 7
number: 3
article_number: 035402
issn: 2475-9953
citation:        Al-Hamdani, Yasmine S;    Zen, Andrea;    Michaelides, Angelos;    Alfè, Dario;      (2023)    Mechanisms of adsorbing hydrogen gas on metal decorated graphene.                   Physical Review Materials , 7  (3)    , Article 035402.  10.1103/physrevmaterials.7.035402 <https://doi.org/10.1103/physrevmaterials.7.035402>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10167826/1/PhysRevMaterials.7.035402.pdf