Photocatalytic Tandem Reaction for Urea Synthesis From Atmospheric CO 2 and N 2

ABSTRACT Photocatalytic urea synthesis directly from atmospheric CO 2 and N 2 offers a sustainable route to bypass the energy‐intensive Bosch–Meiser process, yet simultaneously achieving CO 2 capture and reduction, N 2 activation, and C─N coupling within a single system remains challenging. Herein, we report a two‐step tandem platform combining ionic‐liquid‐modified metal–organic framework (IL@PCN‐250‐Fe 2 Co) with a trinuclear copper‐based covalent organic framework (HTP‐Cu 3 ‐imi‐COF) for urea photosynthesis from air. The IL@MOF captures atmospheric CO 2 and photoreduces it to CO, while HTP‐Cu 3 ‐imi‐COF couples the generated CO with ambient N 2 into urea. This synergistic tandem configuration delivers a urea production rate of 259.87 µg·g cat −1 ·h −1 under air, marking the first demonstration of photocatalytic urea synthesis from atmospheric CO 2 and N 2 . In situ spectroscopic measurements and DFT calculations reveal that the imidazole‐functionalized HTP segments act as hole‐rich oxidation domains, promoting water oxidation to generate *OH species that oxidize locally enriched N 2 to *NO intermediates. Simultaneously, the Cu 3 clusters serve as electron‐rich centers for CO adsorption and activation, forming *CO that couples with *NO via the critical *OCNO intermediate toward urea formation. This work not only showcases the first photocatalytic urea synthesis from air but also establishes a modular paradigm for cascade catalysts that integrate capture and conversion toward sustainable chemical transformations.