Trimetallic MOFs-derived Fe-Co-Cu oxycarbide toward peroxymonosulfate activation for efficient trichlorophenol degradation via high-valent metal-oxo species

Advanced oxidation processes based on high-valent metal species have attracted much attention due to their high reactivity and selectivity in degrading refractory organic pollutants, but the preparation of such catalysts remains a great challenge. Herein, FeCoCu-nitrogen-doped carbon (FeCoCu-NC), a trimetallic catalyst capable of producing high-valent metal species, was synthesized by direct carbonization of core–shell Metal-organic frameworks (MOFs). The rationally designed catalyst exhibited high catalytic activity in wide pH range and high resistance to common radical scavengers, anions and natural organics. The incorporation of Cu in FeCoCu-NC (TNCX) not only enhanced the catalytic activity but also changed the activation mechanism of peroxymonosulfate (PMS) from a radical pathway to a non-radical pathway dominated by high-valent metal species. In addition, the TNC5/PMS system showed higher trichlorophenol (TCP) removal efficiency and PMS utilization compared to the radical-dominated FeCo-NC/PMS system and the 1O2-dominated CoCu-NC/PMS system. This study provides a facile strategy to the preparation of advanced catalysts from multi-metal MOFs and is expected to provide guidance for the design of heterogeneous high-valent metal catalysts.