Trinuclear Cu(I) Metal–Organic Framework Inspires the Activation of ^*CO₂ Via Electrostatic Tension to Boost the Electrochemical Conversion of CO₂‐to‐Methanol

Abstract The metal–organic frameworks (MOFs) as favorable candidates, are applied to the reduction reaction of CO₂ due to the unique affinity for CO₂ molecules and abundant monometallic active sites. However, most MOF‐based electrocatalysts require a carbonization process to overcome their potentially poor conductivity and inert catalytic activity. Here, a semiconducting trinuclear Cu(I)‐MOF undergone low‐temperature activation (CuTz‐1‐300) is directly employed as an electrocatalyst for producing methanol. The CuTz‐1‐300 achieves a methanol faradaic efficiency of 56.41% at the working potential of −0.97 V versus the reversible hydrogen electrode in 0.5 m KHCO₃ electrolyte. The experiments and DFT calculations imply that the generation of ^*COOH is the rate‐determining step for methanol, and ^*CO prefers to be further reduced instead of releasing as a CO product. Specifically, the unique CuN₃ is correspond to nearby BF_4,⁻ producing subtle synergistic electronic effects that CO₂ binding with a relatively strong C···F interaction to BF₄⁻ and weak C─H···O interactions from phenyl groups to enhance the localized CO₂ concentration by electrostatic tension. This work demonstrates the use of ionic MOF with positive univalent Cu to improve the efficiency of electrocatalytic CO₂ reduction.