Screening and prediction of metal-doped α-borophene monolayer for nitric oxide elimination

Abstract

NH3 synthesis from air pollutants (NO) exhibits an attractive alternative method to the traditional Haber–Bosch industrial process. However, it is still challenging due to the kinetic limitations of the N–O bond, which is difficult to break directly, and the selectivity of the final product. Herein, the spin-polarized density functional theory method was applied to explore and design high-efficiency nitric oxide reduction reaction (NORR) catalysts based on the two-dimensional α-borophene monolayer (BM-α) which are doped with transition metals. The catalytic activity of metal-doped α-borophene monolayers (M@BM-α) depend on the binding energy of ∗N (ΔG∗N) and the d-band center (Ɛd), which are applied as the descriptors for the screens of promising catalyst from 23 candidates. This strategy can efficiently and reliably explore the intrinsic correlation between the catalytic activity and descriptors toward efficient NORR catalysts. Furthermore, the Gibbs energy difference of ΔG∗H and ΔG∗NO are also applied as a descriptor to evaluate the selectivity toward the NORR. Overall, Mo@BM-α, Hf@BM-α, Co@BM-α, and Pd@BM-α have the favorable limiting potentials of 0.36 V, 0.24 V, −0.004 V, and −0.25 V, respectively. Furthermore, Hf@BM-α, Co@BM-α, and Pd@BM-α can also strongly suppresses the competing hydrogen evolution reaction with ΔG∗H of −1.26 V, 1.16 V, and 1.12 V, respectively. Then, the descriptors of ΔG∗N and Ɛd provide insight into the intrinsic correlation between the catalytic activity and the structure of M@BM-α. The volcano plot trends are established based on limiting potential and descriptors to screen the best candidates for NO reduction to NH3. The binding energy and electronic properties are executed to explore the relationship between the catalytic activity and structure. This work not only provides an effective and efficient strategy to screen M@BM-α for electrochemical nitric oxide elimination but also provides a feasible strategy for NH3 synthesis and is helpful in screening and designing efficient electrocatalysts for other electrochemical reactions.