Toward High-Performance CO2-to-C2 Electroreduction via Linker Tuning on MOF-Derived Catalysts

Copper (Cu)-based metal-organic frameworks (MOFs) and MOF-derived catalysts are well studied for electroreduction of carbon dioxide (CO2); however, the effects of organic linkers for the selectivity of CO2 reduction are still unrevealed. Here, a series of Cu-based MOF-derived catalysts is investigated with different organic linkers appended, named X-Cu-BDC (BDC = 1,4-benzenedicarboxylic acid, X = NH2, OH, H, F, and 2F). It is found that the linkers affect the faradaic efficiency (FE) for C-2 products with an order of NH2- < OH- < bare Cu-BDC < F- < 2F-, thus tuning the FEC2:FEC1 ratios from 0.6 to 3.8. As a result, the highest C-2 FE of approximate to 63% at a current density of 150 mA cm(-2) on 2F-Cu-BDC derived catalyst is achieved. Using operando Raman measurements, it is revealed that the MOF derives to Cu2O during eCO(2)RR but organic linkers are stable. The fluorine group in organic linker can promote the H2O dissociation to *H species, further facilitating the hydrogenation of *CO to *CHO that helps C-C coupling.

Automated summary

This study investigates the effects of different organic linkers on the electroreduction of CO2 using Cu-based MOF-derived catalysts. The results show that the organic linkers have an impact on the selectivity of C-2 products, with 2F-Cu-BDC derived catalyst achieving the highest faradaic efficiency for C-2 products.