Coupling [Bmim]PF6 and Pd NPs Modulated MOF-Based Material for Synergetic Regulating Electrocatalytic CO2 Reduction.

Abstract

Metal-organic frameworks (MOFs) with a large number of active sites and high porosity are considered to be good platforms for the carbon dioxide electroreduction reaction (CO₂RR) but with confined low conductivity or low efficiency. Here, Pd-[Bmim]PF₆/Cu-BTC with exceptional selectivity and electron-transfer ability is elaborately designed by introducing ionic liquids (ILs) into the MOFs. ILs favor promoting the overall current density of the catalysts, and the introduction of Pd atoms combined with O atoms on the catalyst surface reconfigures into strong Pd-O bonds, improving the desorption efficiency of *CO. The unique structure of the catalyst Pd-[Bmim]PF₆/Cu-BTC leads to a significant improvement of the C₁ product with a high Faraday efficiency (FE) of 99.36%, especially for carbon monoxide (CO) with an FE of 93.18% (-1.1 V_RHE). The exceptional performance of the catalyst is verified by density functional theory (DFT) calculations, and the reduction of the free energy required by *HOCO as a key intermediate for CO production was only 0.12 eV, providing new insights to improve the electrocatalytic performance of MOF-based materials for the CO₂RR. In this research, an effective and promising strategy that configures active sites by larger current density is proposed to enhance the efficiency of the CO₂RR.