In situ post-modification of substoichiometric 2D conjugated MOFs to boost ethylene selectivity in electrocatalytic CO₂ reduction

2D conjugated MOFs (2D c-MOFs) have attracted significant interest in electrocatalysis due to their intrinsic electrical conductivity. Their catalytic performance heavily relied on the metal centers and structures of highly fused polyaromatic hydrocarbon ligands. This led to a considerable challenge in fine-tuning the catalytic performance of 2D c-MOFs. Thus, the modulation of the catalytic performance of 2D c-MOFs through chemical modification has been less explored. Herein, the peripheral defects of substoichiometric 2D c-MOFs are capped with 2,3,5,6-tetrafluoroterephthalonitrile at different doping levels via a facile one-pot post-synthetic strategy. Introducing capping groups not only displays a profound impact on the physical properties of 2D c-MOF but also leads to an enhanced electrocatalytic CO₂ reduction to C₂H₄ with an FE of 54% at −1.2 V vs. RHE. Tuning the catalytic performance of 2D c-MOFs with the chemical modification strategy would notably expand the potential application of 2D c-MOFs.