Abstract
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.
NSTL
Elsevier