Decarboxylation‐Induced Defects in MOF‐Derived Single Cobalt Atom@Carbon Electrocatalysts for Efficient Oxygen Reduction

Abstract Developing transition metal single‐atom catalysts (SACs) for oxygen reduction reaction (ORR) is of great importance. Zeolitic imidazolate frameworks (ZIFs) as a subgroup of metal‐organic frameworks (MOFs) are distinguished as SAC precursors, due to their large porosity and N content. However, the activity of the formed metal sites is limited. Herein, we report a decarboxylation‐induced defects strategy to improve their intrinsic activity via increasing the defect density. Carboxylate/amide mixed‐linker MOF (DMOF) was chosen to produce defective Co SACs (Co@DMOF) by gas‐transport of Co species to DMOF upon heating. Comparing with ZIF‐8 derived SAC (Co@ZIF‐8‐900), Co@DMOF‐900 with more defects yet one fifth Co content and similar specific double‐layer capacitance show better ORR activity and eight times higher turnover frequency (2.015 e s −1 site −1 ). Quantum calculation confirms the defects can weaken the adsorption free energy of OOH on Co sites and further boost the ORR process.