Decoupled Control of CO and Nitrate Reduction Intermediates to Enable Efficient Tandem Urea Electrosynthesis.

The direct electrochemical coupling of CO and nitrate (NO) offers a sustainable alternative to the energy-intensive Bosch-Meiser process for urea synthesis. However, achieving efficient C-N coupling at single active sites remains challenging due to the kinetic mismatch between CO and NO reduction, as well as the intricate multistep proton-coupled electron transfer process. Here, we present a sacrificial template-based strategy to synthesize a two-dimensional (2D)/zero-dimensional (0D) FePS/AgS heterostructure catalyst, enabling the tandem coreduction of CO and nitrate for urea electrosynthesis. Electrochemical studies, measurements, and theoretical calculations together demonstrate that the heterostructures with strongly coupled interfaces not only modulate the electronic structure but also enable decoupled control over NO and CO reduction. FePS offers a moderate conversion rate from NO to ammonia, generating *NH intermediates while mitigating overhydrogenation to ammonia. Meanwhile, AgS with optimized loading facilitates efficient conversion of CO to CO, enabling the diffusion and electrophilic attack of CO on *NH, thereby forming the critical *CONH intermediate for urea production. As a result, the FePS/AgS tandem catalyst achieves a high urea yield rate of 1160.9 μg h mg with a Faradaic efficiency (FE) of 15.4% at -0.7 vs reversible hydrogen electrode, outperforming the individual FePS nanosheets and AgS nanoparticles. This study provides key insights into the rational design of heterostructure catalysts that exhibit strong interfacial interactions and allow for decoupled control over parallel reactions to enhance complex coupling processes.