Decomposition of methyl species on a Ni(211) surface: investigations of the electric field influence

Abstract

Density functional theory calculations are performed to examine how an external electric field can alter the reaction pathways on a stepped Ni(211) surface with regard to the decomposition of methyl species.

Catalytic water dehydrogenation and formation on nickel: Dual path mechanism in high electric fields

“…With a higher energy cutoff (450 eV) and finer k-points mesh of (6×6×1) for Ni(111), the differences in the adsorption energy are only ~0.01 eV from our previous work [28]. More details about the computational setup are given in our previous work [28,31].…”

“…Both the quasi-Newton algorithm [36] and the conjugate-gradient algorithm are applied to relax the ions into their ground state configurations [37,38]. For a p(3×3) [39][40][41] Ni(111) supercell, we apply a four-layer slab [28] and for a p(2×4) Ni(211) supercell, a five-layer metal slab is applied [31]. The differences in the adsorption energies of water on Ni(111) in the presence and absence of an external electric field between a 4-layer and a 5-layer Ni slabs are all less than 0.01 eV.…”

“…More details are also given in our previous work [28,31]. Vibrational frequency calculations performed for the stationary points on the potential energy surface ensure that the initial states (IS) and final states (FS) are stable (with no imaginary frequencies) and the TS have only one imaginary frequency.…”

Catalytic Reaction Rates Controlled by Metal Oxidation State: C−H Bond Cleavage in Methane over Nickel‐Based Catalysts

“…As shown in Figure , the CH species is much more likely to form a carbide‐like species (Ni 4 ‐C) or to form a carbon species (Ni 2 ‐C) at the interface between the Ni cluster and the YSZ support. Both pathways in Figure are more energetically favorable for the CH fragment dissociation to form surface C species than the corresponding pathways over Ni(111) and Ni(211) . In particular, the activation energy ( E a ) for formation of carbide‐like species from the CH fragment dissociation at the interface of the Ni/YSZ+ O cermet is approximately 0.5 eV with a reaction energy (Δ H rxn ) of about −0.8 eV, which is much lower than that required to form a carbon species at the interface ( E a value≈1.0 eV, Δ H rxn ≈0.3 eV).…”

Deposition of Active Component

“…In the context of interfacial coordination chemistry [12,611, the approach has been to use transition metal complexes in aqueous solutions and to investigate the changes, occurring at the liquid-solid interface during deposition, in the interaction between the TMI engaged in the complex and the support. Because of their partly filled d orbitals, any change in their first coordination sphere immediately affects their optical and magnetic properties and can thus be detected by spectroscopy.…”