Molecular orbital calculations of the dissociative adsorption of a hydrogen molecule on a 14 atom nickel cluster

A theoretical study of hydrogen surface coverage over Ni(100)

“…The multiplicity for the most stable state of the NiI4 cluster is 17 [18]. We found, however, in our calculations that when two hydrogen atoms are chemisorbed the multiplicity decreases to 15 [7]. The ready explanation is that electrons from the hydrogen are paired with those of the surface.…”

“…These results, particularly for G-I, and E-E, , suggest that chemisorption occurs more readily at the borders or at surface defects [7]. Hence, at very low coverage, when only independent and noninteracting chemisorbed hydrogen molecules are found on the surface, all of these structures may be present with a given probability factor determined by their relative energies.…”

“…A preliminary study of the diffusion of a single chemisorbed hydrogen through the surface channels while the other chemisorbed hydrogen remains at the border has also been reported previously [7].…”

Dynamics of the D2 + Ni(100) collision system: Analysis of the reactive and inelastic channels

“…Russel et al 9 have reported observing a molecular adsorbed state of the H 2 on a Ni(111) surface at T =87 K. Hayward and Taylor reported a threshold energy of 0.02 eV for H 2 and D 2 sticking on this Ni surface 8. All these calculations including Ruette et al 23 are consistent in that the dissociation of H 2 over a bridge site is found to have a substantially lower barrier than to the dissociation over an atop site. A similar trend is found with the results of Seigbahn et al 22 for the dissociation of H 2 on a Ni(100)‐like face of a Ni cluster.…”

“…The interaction of small molecules such as D 2 , CO, etc., with surfaces has been a highly active research area for many years 1–30. Numerous studies of reactions of H 2 /D 2 with clean Ni surfaces 7–14, 22–30 exist. An understanding of the dissociative chemisorption (DC) process, its dependence on the collision and internal energies of the molecule, and on the surface topology is very important.…”