Heterogenization of Porphyrin into PCN‐222 as Oxidation Catalysts: Comparison in Terms of Reusability

Abstract Although heterogeneous catalysts can be seperated from reaction media easily, catalyst efficiency is often decreased compared to homogeneous counterparts. In this study, catalytic oxidation of thymol and carvacrol were investigated using micron and nano‐sized PCN‐222(Fe) as heterogeneous catalysts and water soluble Fe‐porphyrin complex (FePTC) as homogeneous catalyst in the presence of peroxymonosulfate (PMS). Fe‐porphyrin complexes is well‐known catalyst for oxidation reactions. PCN‐222(Fe), a Zr‐based mesoporous MOFs utilizing porphyrin as organic linker, exhibits similar catalytic performance compared to FePTC for the first use. However, higher conversion values were achieved in PCN‐222(Fe) for the second cycles compared to the homogeneous systems highlighting the importance of heterogeneous MOF system. Thymoquinone (TQ) selectivities of the carvacrol oxidation are 5 and 8 times higher than homogeneous system in the second cycle for nano‐ and micro‐PCN222(Fe), respectively. Importantly, PCN‐222(Fe) can be used for at least 3 cycles with the reduced PMS:catalyst mole ratio.