MOF-derived single site catalysts with Electron-Rich Fe-N4 sites for efficient elimination of trichloroacetamide DBP

Herein, Fe/Co was firstly co-doped on zeolitic imidazolate framework-8 and then calcination to form electron-rich Fe-N4 single site catalysts ( eFeNSCs). The eFeNSCs are composed of FeCo nanoparticles (∼5 nm) surrounded by Fe-N4 active sites, giving the sites negatively charged. The electrochemical in-situ Fourier transform infrared reflection (FTIR) spectroscopy and linear sweep voltammetry analysis demonstrate that the eFeNSCs promote the adsorption of trichloroacetamide and facilitate the C-Cl bond breaking, following a concerted mechanism. Over 97% trichloroacetamide removal, 90% of dechlorination selectivity, and 37% of current efficiency were achieved on eFeNSCs within 90 min at −1.2 V, which are significantly superior to Fe-N4 single site catalysts (FeNSCs) without FeCo nanoparticle. The high dechlorination selectivity of the eFeNSCs brought in the lower genotoxicity of the treated solution, which has been firstly demonstrated by SOS/umu tests. This study provides a new strategy in designing electron-rich single sites electrocatalysts for efficient elimination of disinfection by-products.