Electrochemical Active MOF Nanoparticles/Carbon Composite for the Electroreduction of CO2 into Valuable Chemicals

Abstract

The present work suggests the effectiveness of the composition method to assist non-conductive MOFs to participate in electrochemical applications. We propose a new approach to grow MOF nanoparticles into conductive porous carbon–HKUST-1. When operated in a CO2-saturated aqueous solution, the composites exhibit excellent electrochemical performances, including a low onset potential (-0.58 V) and large reduction currents (-17 mA.cm-2 at -1.0 V), which is considerably high compared to usually reported MOF-based beyond CO electroreduction. The strong π- π interaction between the aromatic linkers and the graphitic carbon proved advantageous in inducing high lateral conductivity of up to 17.2 S m-1 to the composite. EPR investigation of the unpaired electrons on the Cu atoms also disclose that the induced conductivity influences the metal centers. Electrochemical studies reveal high electroactive coverage of 155 nmol. Besides these factors, the excellent durability of the composite is worth noticing. The composite stabilizes the active material, and after 12 hours of constant operation, the electrochemical response was the same. Most importantly, the composite produces formic acid, a valuable chemical commodity, within a short time interval of 15 minutes.