Efficient Solar Driven Upgrading of N₂ to Urea Through Photoredox Reactions on Pt Cluster/TiO₂

Abstract Synthetic nitrogen fertilizers, such as urea, are instrumental in augmenting agricultural output and addressing the demands of a growing population. Nevertheless, conventional urea production heavily relies on energy‐intensive processes. In this study, an environmentally friendly photocatalytic method is proposed for directly and selectively synthesizing urea from nitrogen (N₂) and methanol (CH₃OH using a Pt cluster‐decorated TiO₂ catalyst (Pt cluster/TiO₂). Remarkably, the Pt cluster/TiO₂ exhibits outstanding urea synthesis performance with a rate of 105.68 µmol g⁻¹ h⁻¹ and N‐selectivity of 97.29 ± 0.79%, representing the highest level of photocatalytic urea synthesis from N₂. Further analysis with density functional theory (DFT) calculation reveals that the “σ–π*” donor–acceptor interaction occurred between Pt clusters and N₂, efficiently reducing the N₂ hydrogenation barrier. EPR experiments demonstrate that photogenerated electrons (e⁻) and hole (h⁺) are synchronously consumed through N₂ reduction and CH₃OH oxidation, thereby accelerating urea synthesis. The crucial step of C─N coupling is initiated by the reaction between *NH─NH and *CHO intermediate, facilitated by the low energy barrier on Pt cluster/TiO₂. This work suggests an mild route of urea production and provides profound insights into the underlying chemistry of the C─N coupling reaction, which can guide the sustainable synthesis of essential indispensable chemicals.