Boosting Singlet Oxygen Oxidation of Micropollutants at an Enzyme-like Bifunctional Single-Atom Catalyst Interface
Dezhi Kong, Yafei Fan, Feifei Wang, Fangyu Zhang, Qi Zhao, Zhaoli Sun, Jianfei Yao, Menghui Chu, Wang Guo, Guanyun Zhang, Zhaoyong Guan, Hua Sheng, Yifeng Wang
Abstract
Singlet oxygen ( 1 O 2 ) plays a critical role in oxidation reactions, yet improving its reactivity with substrates remains a significant challenge. This study reports an enzyme-like bifunctional catalyst, Co–N 2 O 2 /NC, which can efficiently activate peroxymonosulfate (PMS) with high selectivity and nearly quantitatively generates 1 O 2 without producing other reactive oxygen species to achieve high reactivity. Notably, it significantly increases the bimolecular reaction rate constant between 1 O 2 and waterborne micropollutants, as demonstrated by the over 1400-fold enhancement in 4-chlorophenol (4-CP) oxidation compared to that in the bulk solution. Enzyme-like catalytic kinetics were observed, with N-sites of the N-doped carbon support serving for activating 4-CP via interfacial electronic interactions, while Co activates PMS to generate 1 O 2 . The interfacial charge transfer lowers the energy barrier for 1 O 2 to approach the aromatic ring of 4-CP, which is the rate-limiting step in the oxygenation reaction. Our findings lay the foundation and offer guidance for designing catalysts that facilitate the efficient generation and use of 1 O 2, expanding its application to a broader range of oxidation processes.