Construction of dual active sites on diatomic metal (FeCo-N/C-x) catalysts for enhanced Fenton-like catalysis

High metal loading of single-atom catalysts enables excellent catalytic activity, but possibly causes serious aggregation problem. Herein, a series of diatomic FeCo-N/C-x (x represents metal content) were skillfully designed and applied to improve the catalytic activity for peroxymonosulfate (PMS) activation toward degrading organic micropollutants. The unprecedented dual active sites, referring to Fe(N-3)-Co(N-3) moiety and FeCo alloy, are constructed on the obtained FeCo-N/C-x, thereby exhibiting significantly greater performance toward degrading aqueous phenol (e.g., 0.316 min(-1) for FeCo-N/C-3) via PMS activation, compared with those of traditional single-atom Co-N/C (0.011 min(-1)) and Fe-N/C (0.018 min(-1)). Combined experimental and theoretical calculations demonstrate the independent functions of dual active sites, in which Fe(N-3)-Co(N-3) and FeCo alloy can decrease the energy barrier of O-O bond cleaving resulting in the formation of high-valent FeCo=O reactive species and singlet oxygen, respectively. This study opens up a new platform toward constructing dual active sites for enhanced Fenton-like catalytic activity.

Automated summary

In this study, a series of diatomic catalysts were designed to enhance the catalytic activity for peroxymonosulfate (PMS) activation. The constructed dual active sites showed significantly greater performance in degrading organic micropollutants compared to traditional single-atom catalysts. Experimental and theoretical calculations demonstrated the independent functions of the dual active sites, providing new insights towards enhanced Fenton-like catalytic activity.