High-Throughput Theoretical Screening of Single-Atom Catalysts for Electrochemical Urea Synthesis

Electrochemical urea synthesis offers a promising approach for sustainable nitrogen and carbon utilization, yet its progress is hindered by the unclear reaction mechanism and the lack of effective catalyst design principles. Here, we conduct a high-throughput screening of over 40 MN₄C-type single-atom catalysts (SACs) to identify promising candidates for electrochemical urea synthesis. This strategy improves screening efficiency by 94.8% compared to conventional methods. Our analysis demonstrates that Ti─, V─, Nb─, Mo─, and Hf-N₄C catalysts concurrently fulfill the essential criteria, including thermodynamic stability, favorable adsorption of small molecules, suppression of competing reactions, and low energy barriers for both hydrogenation and C-N coupling. Mechanistic investigations reveal two distinct C-N coupling pathways and demonstrate that hydrogenation of *N species is a prerequisite for subsequent coupling. Notably, we reveal a linear correlation between the limiting potentials of NO₃ ^- reduction and overall urea synthesis, establishing *NO₃ → *N activity as a reliable descriptor for catalyst screening. This work provides mechanistic insights and a predictive framework for the rational design of efficient urea electrocatalysts.