Ligand Engineering of Cu-Based Metal–Organic Framework for Enhanced Electrocatalytic Urea Synthesis from N2 and CO2

The electrocatalytic reduction in N2 and CO2 into urea under ambient conditions provides a promising strategy for sustainable nitrogen fixation and carbon utilization. However, the low activity and poor selectivity toward urea limit its practical application. Herein, a dual-ligand Cu-based metal–organic framework (Cu-BTC/NH2BDC) was constructed via ligand engineering strategy. The introduction of 2-NH2BDC modulated the electronic structure of Cu sites, generating electron-enriched Cu centers that facilitate CO2 activation, while the hydrogen bonding interaction between the amino and carboxyl groups promotes the activation of N2. As a result, the optimized Cu-BTC/NH2BDC catalyst achieved a urea yield of 6.59 mmol g−1 h−1 with a Faradaic efficiency of 22.85% at −0.2 V versus reversible hydrogen electrode (vs. RHE), outperforming single-ligand counterparts. In situ Raman spectroscopy measurement revealed enhanced the formation of *CO, *NN, and C-N intermediates, indicating improved C-N coupling efficiency. This work provides a feasible strategy for regulating active sites in MOF-based catalysts toward efficient urea electrosynthesis.