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

Metal-organic frameworks (MOFs) have been widely studied for electrochemical CO2 reduction reaction (CO2RR). 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 CO2RR activity with HKUST-1 structural reconstruction. During the CO2RR 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).

Automated summary

Research has shown that during the CO2 reduction reaction process, HKUST-1 will successively reconstruct into two different structures over time: 3D nanospheres composed of numerous small fragments and a 3D nano-network composed of cross-linked nanobelts. The former exhibits better catalytic activity due to more active sites, lower charge transfer resistance, and a 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).