Hydrogen-Bond-Mediated C–N Coupling Enables Efficient Electrocatalytic Urea Synthesis from CO ₂ and N ₂

The electrocatalytic coupling of carbon dioxide (CO2) and nitrogen (N2) to produce urea offers a promising strategy for mitigating greenhouse gas emissions while enabling the storage of renewable energy. However, its practical application is hindered by poor selectivity and limited catalytic activity, primarily due to the complex multistep reaction pathway involving multiple reactants and competing side reactions. Therefore, a new four-step screening strategy based on density functional theory calculations is proposed to efficiently identify electrocatalysts for urea synthesis. Among 27 transition metal doped oxidized black phosphorus (TM@OBP) single-atom catalysts, Ru@OBP, Mn@OBP, and Fe@OBP are identified as highly active candidates, exhibiting low limiting potentials of −0.39, −0.62, and −0.91 V, respectively. Notably, hydrogen bonding interactions between the *NH2NH2 intermediate and the OBP support are found to significantly lower the energy barrier for C–N coupling, thereby promoting urea formation. In addition, competing side reactions such as CO2 reduction (CO2RR), N2 reduction, and the hydrogen evolution reaction are effectively suppressed on these catalysts, resulting in enhanced urea selectivity. This work not only identifies three efficient electrocatalysts for urea synthesis but also establishes a generalizable screening methodology that may guide the rational design of electrocatalysts for other complex multistep reactions.