Efficient and Durable Single-Atom Fe Catalyst for Fenton-like Reaction via Mediated Electron-Transfer Mechanism

Efficient approaches toward selective removal of the emerging organic pollutants are of critical importance to the well-being of the human health and the eco-system. Peroxymonosulfate-involved advanced oxidation process is promising in water treatment due to a couple of intrinsic advantages of the reaction system, and the development of an efficient catalyst is essential to the real application of this technique. In this work, a series of single-atom Fe catalysts were fabricated via a facile method, and the single-atom center was identified to be in a Fe–N4 configuration by Fe K-edge X-ray absorption spectroscopy. On the optimum catalyst with 4.8 wt % Fe single atom, 22 ppm BPA could be eliminated within 40 s under mild reaction conditions, affording a remarkable pseudo-first-order reaction rate constant of 8.4 min–1. The durability of the catalyst was tested with a fixed-bed flow reactor, and 55.2 L of polluted water with 10 ppm BPA could be treated with a removal rate of >95% by 1 g of catalyst. Through a series of probe reactions and spectroscopic analysis, the mediated electron-transfer mechanism was identified to be dominant during the pollutant degradation process.