Constructing a Dual-Atom Catalyst Enables Electrocatalytic Synthesis of Urea by Coreduction of CO and N₂

Combining density functional theory calculations and a constant-potential model, the electrocatalytic performance for urea production on 3 homoatomic and 30 heteroatomic dual sites anchored on graphene (M₂-N₆@G and MM'-N₆@G, M = Cr, Mo, and W, M'≠ M) was examined using N₂ and CO as feedstocks. The homoatomic catalysts encounter serious selectivity issues in that the formation of the intermediate of *NH₂CHONH dominates over that of the targeting product *NH₂CONH₂ due to a strong N adsorption strength. With the introduction of M', MoFe-N₆@G stands out from 30-plus candidates owing to its preference toward side-on adsorption of N₂ and unfavorable formation of *NH₂CHONH. The high activity originates from a relatively weaker N adsorption, and the elusive selectivity is rooted in a moderate charge transfer from MM' to N atoms. Our results underscore the role of adsorption strength of N in the electrocatalytic performance for urea production, offering a fundamental perspective for further optimizing the electrocatalysts.