Understanding Structure-activity Relationship on Metal-Organic-Framework-Derived Catalyst for CO2 Electroreduction to C2 Products

Graphical The structural reconstruction of HKUST-1 on carbon fiber paper and the activity in CO 2 electroreduction is investigated. The HKUST-1 initially reconstructed into highly active 3D nanospheres and then into stable nanobelts after 120 minutes. The 3D nanospheres structure shows the best Faradaic efficiency of C 2 products up to 58.6 %. Metal-organic frameworks (MOFs) have been widely studied for electrochemical CO 2 reduction reaction (CO 2 RR). However, the application of negative potential tends to trigger its structural reconstruction and component alteration. It is of great significance to study the relationship between the structural evolution of MOF-derived materials and product selectivity under the reaction conditions. Herein, we fabricate a HKUST-1 thin film on carbon fiber paper by a facile electrodeposition approach to investigate the variation of CO 2 RR activity with HKUST-1 structural reconstruction. During the CO 2 RR process, the HKUST-1 reconstructs into two structures successively over time: 3D nanospheres composed of numerous small fragments and 3D nano-network composed of cross-linked nanobelts in different directions. The former shows a better catalytic activity due to more active sites, lower charge transfer resistance and higher Cu + /Cu 0 ratio. The optimum Faradaic efficiency (FE) of C 2 products (ethylene and ethanol) reaches 58.6 % at −0.98 V versus reversible hydrogen electrode (RHE).