Design of a High-Performance Electrocatalyst for N₂ Conversion to NH₃ by Trapping Single Metal Atoms on Stepped CeO₂

Abstract

Single-atom catalysts (SACs) have recently been shown to have high performance in catalyzing the synthesis of NH 3 from N 2 . Here, we systematically investigated a series of single transition metal atoms anchored on stepped CeO 2 (CeO 2 -S) to screen the potential electrocatalysts for a N 2 reduction reaction (NRR) via density functional theory computations. We first demonstrated that these SACs are stable via large calculated binding energies. Second, we evaluated the adsorption of *N 2 over CeO 2 -Ssupported single atoms. Here, those systems that can activate N 2 molecules were selected as candidates. We then showed that CeO 2 -S-supported single Mo and Ru atoms have high catalytic activity for NRR via low limiting potentials of −0.52 and −0.35 V, respectively. Meanwhile, the competitive hydrogen evolution reaction is highly suppressed over these two SACs because the adsorption of *N 2 is prior to *H. Finally, the origin of the NRR activity over these SACs was investigated. This work offers useful insights into designing high-performance CeO 2 -based electrocatalysts for NRR.

A Theoretical Evaluation of Possible N2 Reduction Mechanism on Mo2B2

“…Effective activation of the inert triple bond of N 2 which needs a lot of energy, is the prerequisite for a high‐performance catalyst of NRR. [ 18 ] Therefore, chemical adsorption is the basis for activating the N≡N triple bond. And then, according to the structure of 2D Mo 2 B 2 depicted in Figure 1a, we search for the six kinds of different positions by considering both vertical and horizontal initial adsorption configurations for N 2 adsorption to obtain the stable configuration.…”

Recent Advances of CeO2‐Based Electrocatalysts for Oxygen and Hydrogen Evolution as well as Nitrogen Reduction

“…[158] Qi et al systematically investigated 28 single transition metal atoms anchored on stepped CeO 2 (CeO 2 À S) by DFT calculation to screen potential electrocatalysts for NRR. [159] They first proved that 26 SACs were stable by calculating the binding energy. Secondly, the adsorption of *N 2 is energetically preferable in 8 M/CeO 2 À S catalysts with suppressed HER.…”

Development of Electrocatalysts for Efficient Nitrogen Reduction Reaction under Ambient Condition

“…Especially, the Mo and Ru atoms showed higher catalytic performance with a low energy barrier of 0.52 and −0.35 eV, respectively. [ 44 ] Recently, Qiao et al. built up a picture for transition metal single‐atom catalysts (TM‐SACs) on g‐C 3 N 4 in e‐NRR.…”