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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/12926

Title: Hydrazine adsorption on perfect and defective fcc nickel (100), (110) and (111) surfaces: a dispersion corrected DFT-D2 study
Authors: Menkah, Elliot S.
Dzade, Nelson Y.
Tia, Richard
Adei, Evans
Leeuw, Nora H. de
Keywords: Density Functional Theory (DFT)
Hydrazine adsorption
Fuel cells
Nickel surfaces
Issue Date: 2019
Publisher: Elsevier B.V.
Abstract: We present density functional theory calculations, with a correction for the long-range interactions, of the adsorption of hydrazine (N2H4) on the Ni (110), (100), and (111) surfaces, both defect-free planes and surfaces containing point defects in the form of adatoms and vacancies. Several low-energy adsorption structures for hydrazine on the perfect and defective surfaces have been identified and compared. The hydrazine molecule is shown to interact with the Ni surfaces mainly through the lonepair of electrons located on the N atoms, forming either monodentate or bidentate bonds with the surface. The strength of N2H4 adsorption on the perfect surfaces is found to be directly related to their stability, i.e. it adsorbs most strongly onto the least stable (110) surface via both N atoms in a gauchebridge configuration (Eads = −1.43 eV), followed by adsorption on the (100) where it also binds in gauche-bridge configurations (Eads = −1.27 eV), and most weakly onto the most stable (111) surface via one N−Ni bond in a trans-atop configuration (Eads = −1.18 eV). The creation of defects in the form of Ni adatoms and vacancies provides lower-coordinated Ni sites, allowing stronger hydrazine adsorption. Analysis into the bonding nature of N2H4 onto the Ni surfaces reveals that the adsorption is characterized by strong hybridization between the surface Ni d-states and the N p-orbitals, which is corroborated by electron density accumulation within the newly formed N−Ni bonding regions.
Description: An article published by Elsevier B.V.
URI: http://hdl.handle.net/123456789/12926
Appears in Collections:College of Health Sciences

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