Two‐Dimensional Metal Covalent Organic Polymers with Dirhodium(II) Photoreduction Centers for Efficient Nitrogen Fixation

Photocatalytic nitrogen fixation is a green method for converting N2 to NH3, but it remains a challenging task due to the lack of effective photocatalysts. Herein, a series of porous metal covalent organic polymers (MCOPs) with the integration of dinuclear rhodium(II) catalytic center were rationally constructed for photocatalytic N2 fixation. Interestingly, the porous MCOPs had double‐layers two‐dimensional (2D) structures with the coordinated Rh(II) as point of registry. The photocatalytic experiment showed that Rh‐TAPA with significant donor‐acceptor (D‐A) features exhibited a high activity toward NH3 production with a rate of 319.8 μmol g−1 h−1. The electron transfer process, N2 adsorption and activation mechanism of RhCOPs were further investigated through comprehensive characterisation, including DFT calculations and in situ characterization. This work provided a valuable insight into the photocatalytic N2 fixation process with porous materials.