DFT Study of Hydrogen Adsorption on Palladium Decorated Graphene

Abstract

The adsorption of several molecular and dissociative dihydrogen systems on a Pd-decorated graphene monolayer was studied using the density-functional theory. Our calculations show that the most favorable graphene-supported coordination structure is similar to the PdH 2 complex in vacuum, where the H-H bond is relaxed but not dissociated. We also computed overlap populations corresponding to bonds and atomic orbital interactions in order to study the evolution of the chemical bonding. During the decoration process with Pd, we detected a weakening of C-C bonds close to the adsorption site and the formation of strong C-Pd bonds, coming from interaction between C 2p z and Pd 5s, 5p z , and 4d z 2 orbitals. After H 2 molecule adsorption, the H-Pd bond is formed by the H 1s orbital overlap with the Pd 5s orbital, but this interaction became stronger during the atomic hydrogen adsorption. The objective of this work is to contribute to the understanding of the hydrogen uptake of Pd-doped graphene surfaces.

Hydrogen storage on nitrogen induced defects in palladium-decorated graphene: A first-principles study

“…Such a single H 2 molecule adsorption behavior is also reported in Ref. [45]. A similar analysis method is performed for the case of two H 2 molecules adsorption as shown in Fig.…”

DFT study of H2 adsorption on Pd-decorated single walled carbon nanotubes with C-vacancies

“…Therefore, a Kubas type s-complex is again originated. These findings are in agreement with previous DFT-SIESTA calculations using an H 2 /Pd/graphene model [26], where the most stable graphene-supported PdH 2 structure is similar to the dihydrogen complexes synthesized by Kubas [25]. In the same way, Xiao et al [23] did not find hydrogen dissociation during the adsorption of H 2 on the bridge site of a Pddecorated (8,0) SWCNT, with a comparable HeH elongation.…”

First-principle study of methanol adsorption on Ni (Pd)-decorated graphene

“…When an M atom was located on the top and on the hollow sites of the graphene, it reoriented to the top of bridge sites. Our finding is in agreements with Juan et al's results [30]. To ensure the most preferred location of Ni (Pd) atom, we optimize the atoms added on different lengths to the bridge site of the sheet and compare the relative stability.…”