Density functional study of hydrazine N–N bond cleaving on 3d metal surfaces

Abstract

Theoretical calculations based on dispersion-corrected density functional theory (DFT-D2) has been performed to investigate hydrazine adsorption and N-N bond cleaving on closed packed surfaces of 3d metals: Fe(110), Co(0001), Ni(111), Cu(111), and Zn (0001). The activation energies of N-N bond cleaving of hydrazine on each surface are estimated using climbing-image nudged elastic band (CINEB) method. The results showed that the activation energies for this process have increasing trend from Fe(110) to Zn(0001). By examining the electronic structure of the adsorbed hydrazine, it is found that this trend is related to occupation of derived 6σ* orbitals. It is also found that approximate linear relationship between reaction energy and activation energy (the Brønsted-Evans-Polanyi (BEP) relationship) holds for those surfaces.

Understanding of Selective H2 Generation from Hydrazine Decomposition on Ni(111) Surface

“…Meanwhile, the cis-conformation has a more stretched N–N bond than anti- and gauche-conformation probably because both N atoms bond to surface (see Table and Figure ). As a result, a smaller barrier height of 0.36 eV is needed to cleave the N–N bond, which is consistent with previous work …”

Hydrazine Oxidation Electrocatalysis

“…Mechanistic HzOR studies are harder to perform on nanoparticles than on single-crystalline metal surfaces, since the high-energy surface of nanoparticles is typically less defined and even more in flux during catalysis. Theoretical calculations predict that the selectivity of the oxidation and decomposition routes will depend on the exposed metal facet and the local structure. − ,,− Thus, precise control of the nanoparticle shape could expose specific crystal facets or active defects and even tune their electronic structures. This has been demonstrated experimentally for shape-selected single-crystalline nanoparticles, such as the Pd(110) or the Rh(100) surfaces, which were found to be more active toward the HzOR than other facets.…”

Development Trends on Nickel‐Based Electrocatalysts for Direct Hydrazine Fuel Cells

“…Density functional theory (DFT) is an alternative tool to provide more insights into catalyst reactivity and adsorption mechanism of N 2 H 4 at an atomic level [169–178] . For example, Menkah et al.…”

“…Density functional theory (DFT) is an alternative tool to provide more insights into catalyst reactivity and adsorption mechanism of N 2 H 4 at an atomic level. [169][170][171][172][173][174][175][176][177][178] For example, Menkah et al studied the adsorption properties of N 2 H 4 not only on Ni(100), (110) and (111) perfect surfaces but also at vacancies and adatoms. [88] Based on analyses, the N 2 H 4 displayed a good activity to bind with Ni surfaces via a lone-pair of electrons of N atoms, forming either monodentate or bidentate bonds with the surface.…”