Silver frameworks based on a tetraphenylethylene-imidazole ligand for electrocatalytic reduction of CO 2 to CO.

Metal-organic frameworks (MOFs) can be used as electrocatalysts for the CO 2 reduction reaction (CO 2 RR) because of their well-dispersed metal centers. Silver is a common electrocatalyst for reduction of CO 2 to CO. In this study, two Ag-MOFs with different structures of [Ag 8 O 2 (TIPE) 6 ](NO 3 ) 4 (Ag-MOF1) and [Ag(TIPE) 0.5 CF 3 SO 3 ] (Ag-MOF2) [TIPE = 1,1,2,2-tetrakis(4-(imidazol-1-yl)phenyl)ethene] were synthesized and used for CO 2 electroreduction. The results show that Ag-MOF2 is superior to Ag-MOF1 and exhibits high CO faradaic efficiency (FE) of 92.21% with partial current density of 29.51 mA cm -2 at -0.98 V versus reversible hydrogen electrode (RHE). The FE CO is higher than 80% in the potential range of -0.78 to -1.18 V. The difference may be caused by different framework structures leading to different electrochemical active surface areas and charge transfer kinetics. This study provides a new strategy for designing and constructing CO 2 electroreduction catalysts and provides potential ways for solving environmental and energy problems caused by excessive CO 2 emission.