Toward High-Performance CO -to-C 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 (CO ); however, the effects of organic linkers for the selectivity of CO 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 = NH , OH, H, F, and 2F). It is found that the linkers affect the faradaic efficiency (FE) for C products with an order of NH  < OH < bare Cu-BDC < F < 2F, thus tuning the FE :FE ratios from 0.6 to 3.8. As a result, the highest C FE of ≈63% at a current density of 150 mA cm on 2F-Cu-BDC derived catalyst is achieved. Using operando Raman measurements, it is revealed that the MOF derives to Cu O during eCO RR but organic linkers are stable. The fluorine group in organic linker can promote the H O dissociation to *H species, further facilitating the hydrogenation of *CO to *CHO that helps CC coupling.