Multidimensional engineering of single-atom cobalt catalysts for ultrafast Fenton-like reactions

Abstract

Single-atom catalyst (SAC)-based Fenton-like systems offer sustainable solutions for water purification, but challenges remain in large-scale SAC production and precise structure engineering. Here we present a facile strategy for laboratory-scale mass production of Co-SACs with multidimensional coordination engineering, where atomically dispersed Co–N4 sites are spontaneously modulated by axial Cl and second-shell S (Co1CNCl/S). The configuration downshifts the d-band centre of active Co sites, enhances charge-transfer capacity and significantly strengthens the Co–O bond with peroxymonosulfate, forming a surface electrophilic intermediate with mild oxidation potential. Consequently, Co1CNCl/S steers peroxymonosulfate activation via a non-radical electron-transfer pathway, achieving selective phenol degradation within 5 min with a turnover frequency of 1.82 min−1, outperforming state-of-the-art catalysts. In a continuous flow, the Co1CNCl/S-packed column achieves effective organic wastewater treatment at just $US0.22 per tonne. This work demonstrates a scalable approach for developing cost-effective SACs for environmental remediation. Despite the considerable potential of single-atom catalysts in water and wastewater treatment, large-scale production is still challenging. A multidimensional coordination approach provides a practical and cost-effective method for the mass production of single-atom catalysts.