Thiophene Linker Modulation in Covalent Organic Frameworks for Enhancing Intermediate Adsorption and Selective Two‐Electron H 2 O 2 Electrosynthesis

ABSTRACT Designing the electronic structure of organic frameworks to modulate the adsorption strength of the OOH * intermediate at active sites represents a crucial strategy for advancing electrochemical H 2 O 2 production. In this study, we incorporated varying amounts of thiophene units into covalent organic frameworks (COFs) to regulate their electronic properties for oxygen reduction reaction (ORR). The electrochemical measurements indicate that the bithiophene‐containing framework (bTDC‐COF) exhibited superior ORR performance and higher H 2 O 2 selectivity compared to its mono‐ and terthiophene analogues. Theoretical calculations reveal that the adsorption energy of the OOH * intermediate as a function of thiophene content followed a typical volcano plot. The carbon sites adjacent to thiophene‐S in bTDC‐COF promote moderate OOH * adsorption and reduce its energy barrier, favoring the two‐electron pathway for efficient H 2 O 2 generation. Consequently, the catalyst delivers an exceptional H 2 O 2 production rate of 15 730.6 mmol g catal −1 h −1 with a Faradaic efficiency of 94.2%, outperforming reported COF‐based electrocatalysts to date.