Cluster expansion method for adsorption: Application to hydrogen chemisorption on graphene

Abstract

A systematic method is presented for determining the ground state of absorbed species on a substrate based on a cluster expansion of the configurational energy. It is shown that the method can determine the ground state of a strongly relaxing system using a few first-principles total energy calculations of small cells only. The method is applied to a particularly challenging case, the two-sided hydrogen chemisorption on a free standing graphene sheet, where, as a function of hydrogen coverage, the carbon hybridization goes from sp 2 to sp 3 . The method should require still fewer calculations and yield still more accurate results in the case of physisorption where longer-ranged strain effects are less important.

Diffusion of hydrogen in graphite: a molecular dynamics simulation

“…Moreover, chemisorption on two-dimensional systems, such as graphene or graphite surfaces, can be important for catalytic processes [5]. The interest on hydrogen as an impurity in solids and on surfaces is not new, and dates back to several decades.…”

“…Also, the diffusion, trapping, and recombination of hydrogen on a graphite surface have been studied by theoretical techniques [15][16][17][18]. In connection with this, atomic hydrogen on graphene has been investigated by several authors using abinitio methods [5,[19][20][21][22][23]. It is generally accepted that chemisorption of a single hydrogen atom leads to the appearance of a defect-induced magnetic moment on the graphene sheet, along with a large structural distortion [19][20][21].…”

Hydrogen transport on graphene: Competition of mobility and desorption

“…In the last few years, interest in the topic has been accentuated by demonstration of the possibility of creating individual layers of sp 2 -bonded carbon (graphene), a material with unique properties that are expected to have many high-tech applications. 1,2 For example, the extremely fast charge carrier transport in graphene makes this material very promising for the development of novel carbon-based nanoelectronic components, whereas the possibility of covering practically the whole graphene surface with hydrogen [3][4][5] opens a way to use graphene as an efficient hydrogen storage material.…”

Cluster Expansions for Thermodynamics and Kinetics of Multicomponent Alloys

“…Although there are several CE studies on ternary alloys, [26][27][28][29][30][31][32] usually a presupposed cluster, such as the irregular tetrahedron in the case of bcc lattices, is selected while ignoring convergence issues. On the other hand, more recent ab initio studies on multinary alloys are not so clear on the formal basis and the actual implementation of the CE [33,34,19,35,36] so that a comprehensive derivation, such as given here, might be desirable. In particular, the generalized Ising model for binary alloys cannot be extended easily to multinary alloys.…”