Design of a High-Performance Electrocatalyst for N 2 Conversion to NH 3 by Trapping Single Metal Atoms on Stepped CeO 2

Single-atom catalysts (SACs) have recently been shown to have high performance in catalyzing the synthesis of NH from N . Here, we systematically investigated a series of single transition metal atoms anchored on stepped CeO (CeO -S) to screen the potential electrocatalysts for a N 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 over CeO -S-supported single atoms. Here, those systems that can activate N molecules were selected as candidates. We then showed that CeO -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 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 -based electrocatalysts for NRR.