Customizing Ionic Liquids Functionalized MOFs Composites with Hydrophobic Interface for Electrochemical CO2 Reduction.

Abstract

The electrochemical carbon dioxide reduction reaction (CO₂RR) to generate feedstocks for chemical products (e.g., carbon monoxide, CO) offers a highly attractive method for achieving the closure of the carbon cycle. Ionic liquids (ILs)-functionalized Cu-based catalyst Cu₂O-HKUST-1/IL₁/PTFE was developed, configuring metal-organic frameworks(MOFs) based materials with high adsorption and multiple active sites. The modified electrocatalysts exhibited high specific surface area, strong CO₂ adsorption capacity, abundant active sites, and fast charge transfer rate. The nucleophilic active site of deprotonation at the C₂ site in imidazole ILs further improved the selectivity of proton migration and CO product generation, which was verified through DFT calculations for the low Gibbs free energy of the generated intermediate interactions. In addition, the hydrophobic interface constructed by PTFE facilitated the inhibition of the hydrogen evolution reaction (HER) and significantly improved the efficiency of CO₂ electroreduction. The Cu₂O-HKUST-1/IL₁/PTFE catalyst manifested a high C₁ Faraday efficiency (FE) up to 96.5% and in particular 92.7% for FE_CO at -1.7 V vs RHE. The present work provides an efficient strategy for configuring ILs-functionalized MOFs-based materials with good hydrophobic interfaces to enhance the efficiency of CO₂ electroreduction to C₁ products.