Dual-reaction-centre enabled concurrent N–C–N coupling for effective urea electrosynthesis

Abstract

Electrocatalytic C–N coupling offers a promising approach to producing urea economically and sustainably. However, the process is often hindered by complex reaction mechanisms and a lack of spatial functional differentiation between CO₂ reduction and C–N coupling in catalysts. To address this issue, we propose designing dual-reaction-centre catalysts (DRCCs) with two spatially independent active sites, each dedicated to a critical reaction step. Through high-throughput methods and theoretical simulations, fifteen 2D metal–organic frameworks PcTM₁–O₈–TM₂ complexes are identified, where TM₁ = Ti, V, Cr, Mo, Tc and TM₂ = Mn, Cr, Fe. These frameworks enable the synchronous activation of NO and CO₂ on separate active centres, facilitating a concurrent N–C–N coupling mechanism. The CO produced by CO₂ reduction at the TM₂ site preferentially inserts into *NO–NO at the TM₁ site, forming a unique *NOCONO precursor. The low onset potentials, reasonable kinetic barriers for N–C–N coupling, and high stability and selectivity of these DRCCs demonstrate outstanding catalytic performance comparable to the benchmark PdCu alloy.