On the H₂interactions with transition metal adatoms supported on graphene: a systematic density functional study

Abstract

The attachment of H to the full set of transition metal (TM) adatoms supported on graphene is studied by using density functional theory. Methodology validation calculations on the interactions of H with benzene and graphene show that any of the vdW corrections under study, the Grimme D2, D3, D3 with Becke-Jonson damping (D3BJ), and Tkatchenko-Scheffler methods, applied on the PBE functional, are similarly accurate in describing such subtle interactions, with an accuracy of almost 2 kJ mol compared to experiments. The PBE-D3 results show that H physisorbs on especially stable d or d TMs. In other 5d metals, and the rightmost 3d and 4d ones, H dissociates, and only for Y, Mn, Fe, and Zr the H binds strongly enough for its storage in the so-called Kubas mode, where the H bond is sensibly elongated. Other metals (Co, Ni, Ru, Rh and Pd) feature also an elongated Kubas mode, interesting as well for H storage. Sc and Ti display a Kubas modes especially suited, given their lightness, for meeting the gravimetric requirements. The H interactions with TM adatoms imply a TM → H charge transfer, although the magnetic moment of the system tends to remain intact, except for the early 5d TMs, where the unpaired electron transfer seems to be associated with the H bond breakage.

Tunning Hydrogen Storage Properties of Carbon Ene–Yne Nanosheets through Selected Foreign Metal Functionalization

“…Moreover, cohesive energies of TM are considerably higher than those of alkali and alkaline-earth metals; therefore, the latter will form clusters with lower probability. Moreover, the H 2 bindings to TMs are usually very strong for the room-temperature applications. − …”

Formation of Mn hydrides from bis(trimethylsilylmethyl) Mn(II): A DFT study

“…The PBE functional 22,23 was used in conjunction with Grimme's D3 dispersion corrections 24 and the 6-311++G** basis set; this approach has been shown to provide reasonable geometry, IR and electronic data for optimised geometries in our previous work as well as in benchmarking against ab initio techniques. [25][26][27][28] Gaussian 09 revision D.01 29 and Gaussian 16 revision A.03 30 have been used to perform all the calculations presented herein.…”

Computational study of H2 binding to MH3 (M = Ti, V, or Cr)

“…This approach has been shown by others 38,39 to provide reasonable geometry, IR and electronic data in benchmarking against ab initio techniques. [40][41][42][43] Both Gaussian 09 revision D.01 44 and Gaussian 16 revision A.03 45 have been used to perform the calculations presented herein;…”