Electrochemical-Assisted Reconstruction of Isoreticular Metal-Organic Framework-8 for Efficient Electroreduction of CO2 to CO

Abstract

Metal–organic frameworks (MOFs) have exhibited great potential for electrochemical CO2 reduction (CO2RR). In this study, Zn-based IR-3 and IR-8 were synthesized to prepare electrocatalysts for CO2RR. It was found that the catalytic activity of both MOF-based materials was much higher than that of bulk Zn foil. Notably, a significant change in IR-3 and IR-8 was observed after CO2RR. The reconstruction process was then investigated using IR-8 as a representative material. Results showed that IR-8 underwent rapid destruction under negative potential, along with the conversion of structural Zn to Zn nanoparticles (NPs) and the release of the organic linker. Moreover, the catalytic activity was found to be reconstruction potential-dependent. When a moderate potential was applied, the formed Zn NPs possessed diameters of tens of nanometers, whereas a high reconstruction potential induced the generation of tiny Zn NPs. Compared to the control samples, the active structure for CO2RR was identified to be the reconstruction-induced Zn NPs whose size and crystalline structure were believed to be the primary factors for CO2RR. This study demonstrates that the electrochemical reconstruction of MOFs may be a promising way to develop efficient CO2RR electrocatalysts.