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

Abstract Photocatalytic nitrogen fixation is a green method for converting N 2 to NH 3 , 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 centers were rationally constructed for photocatalytic N 2 fixation. Interestingly, the porous MCOPs had double‐layers two‐dimensional (2D) structures with the coordinated Rh(II) as the point of registry. The photocatalytic experiment showed that Rh‐TAPA with significant donor‐acceptor (D−A) features exhibited a high activity toward NH 3 production with a rate of 319.8 μmol g −1 h −1 . The electron transfer process, N 2 adsorption and activation mechanism of RhCOPs were further investigated through comprehensive characterization, including DFT calculations and in situ characterization. This work provided a valuable insight into the photocatalytic N 2 fixation process with porous materials.