First-principles calculations of NO and NO₂adsorption on a spinel ZnGaAlO₄(100) surface

Abstract

Density functional theory (DFT) has been used to investigate the properties of NO and NO 2 adsorption on a ZnGaAlO 4 (100) surface. The calculation results show that the minimum surface energy is 2.3073 J m −2 . The configuration of NO adsorbed on the surface is more stable through an N-down orientation due to the strong hybridization between d states and the NO-π orbital. In particular, NO approaches Zn via its N side with an adsorption energy of −23.50 kcal mol −1 , while the comparable value is −44.19 kcal mol −1 for NO 2 adsorbed at Zn, suggesting a higher degree of adsorption stability. In addition, substitution of Al with Ga is responsible for the most stable mode of NO 2 adsorption with a binding energy of −53.40 kcal mol −1 . This demonstrates that the process of desorption of NO 2 is thermodynamically feasible. NO 2 adsorbed on the surface is activated, showing that the adsorption can directly lead to a dissociation of NO 2 . Moreover, the process of dissociation of NO 2 adsorbed at Ga is favored due to a lower energy barrier of activation.

DFT studies of the CH4-SCR of NO on Fe-doped ZnAl2O4(100) surface under oxygen conditions

“…This is consistent with Xiang Chao's research on ZnGaAlO 4 (100) and Pâmella's research on Co 3 O 4 (100) surface. 35 It can be seen from Fig. 3 that the adsorption energy of the O terminal of NO is À1.230 eV to À1.397 eV, while the adsorption energy at the N terminal is higher, the value is À1.578 eV to À2.118 eV.…”

“…This is consistent with Xiang Chao's research on ZnGaAlO 4 (100) and Pâmella's research on Co 3 O 4 (100) surface. 35 …”

“…Zou et al 27 calculated the adsorption properties of NH 3 on the ZnFe 2 O 4 surface. Xiang 35,36 found that the property of NO 2 and NO adsorbed on ZnGaAlO 4 (100) surface.…”

Spin Polarization Enhancement of an Fe3O4(100) Surface by Coadsorption of Atomic Hydrogen and Molecular Nitric Oxide

“…In contrast, a NO molecule prefers the Fe­(B) site via its N-terminal with an adsorption energy of −0.823 eV . The bonding of NO molecules with metallic atoms has also been observed for CuFe 2 O 4 (100), ZnGaAlO 4 (100), and NiO(100) substrates. − The geometric structure of (H, NO) coadsorption can be obtained through the adsorption of either a NO molecule on the H-adsorbed Fe 3 O 4 (100) surface or a H atom on the NO-adsorbed Fe 3 O 4 (100) surface. The H atom and NO molecule bond with surface O1 and Fe­(B) atoms, respectively (Figure ).…”

Effect of O2 on reduction of NO2 with CH4 over gallium-modified ZnAl2O4 spinel-oxide catalyst by first principle analysis

“…Because O and NO segments derive from the dissociation of adsorbed NO 2 , and the configuration of NO adsorption at Zn with N down over spinel ZnGaAlO 4 is the most stable [40], the most stable final states may be O segment adsorbed at Ga site and NO segment located in one adsorption site in Fig. 5(c), where O migration of adsorbed NO 2 to adjacent Ga atom of the surface is obvious.…”