Potassium‐Assisted Fabrication of Intrinsic Defects in Porous Carbons for Electrocatalytic CO₂ Reduction

Abstract The fabrication of intrinsic carbon defects is usually tangled with doping effects, and the identification of their unique roles in catalysis remains a tough task. Herein, a K⁺‐assisted synthetic strategy is developed to afford porous carbon (K‐defect‐C) with abundant intrinsic defects and complete elimination of heteroatom via direct pyrolysis of K⁺‐confined metal–organic frameworks (MOFs). Positron‐annihilation lifetime spectroscopy, X‐ray absorption fine structure measurement, and scanning transmission electron microscopy jointly illustrate the existence of abundant 12‐vacancy‐type carbon defects (V₁₂) in K‐defect‐C. Remarkably, the K‐defect‐C achieves ultrahigh CO Faradaic efficiency (99%) at −0.45 V in CO₂ electroreduction, far surpassing MOF‐derived carbon without K⁺ etching. Theoretical calculations reveal that the V₁₂ defects in K‐defect‐C favor CO₂ adsorption and significantly accelerate the formation of the rate‐determining COOH* intermediate, thereby promoting CO₂ reduction. This work develops a novel strategy to generate intrinsic carbon defects and provides new insights into their critical role in catalysis.