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.