A new strategy for high-valent metal-oxo generation in Fenton-like reactions: high work-function supports favor the generation of high-valent metal-oxo in single-atom catalysts

Recently, an article entitled “Support work-function dependent Fenton-like catalytic activity of Co single atoms for selective cobalt(IV)=O generation” was published in Science Bulletin by Mingce Long's group from the School of Environmental Science and Engineering, Shanghai Jiao Tong University.

In the study, the reaction of Co-SACs activated PMS for Co^IV=O generation was systematically investigated by loading cobalt single atoms on the surfaces of graphene, MnO₂, ZrO₂, and TiO₂ with different prior facets using a strong electrostatic adsorption method. The Co^IV=O generated on Co-SACs was determined by in-situ Co K-edge XAS, and the steady-state concentration of Co^IV=O in Co-SACs/PMS was determined and found to be positively correlated with the work function of supports. The in-situ characterization and theoretical calculations revealed that the supports with a high W_F value like anatase-TiO₂ facilitate the binding of PMS-terminal oxo-ligand to Co sites by extracting Co-d electrons, thus decreasing the generation barrier for the critical intermediate (Co-OOSO₃²⁻). The normalized steady-state concentration of Co^IV=O in Co-TiO₂/PMS system was three orders of magnitude higher than that of free radicals, and 1.3- to 11-fold higher than that generated in other Co-SACs/PMS systems. The Co-TiO₂/PMS continuously and efficiently removed sulfamethoxazole (SMX) from water under continuous flow operation. Overall, these results underscore the significance of support selection for enhanced generation of high-valent metal-oxo species and efficient PMS activation in supported metal SACs.

 

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