Bidentate Binuclear Coordination Configuration for Peroxymonosulfate Catalytic Regulation through Incorporation of CuFeOx to Iron-Based Metal Organic Frameworks

The scheme of coordination bridge modification provides a new vision for regulating the catalytic pathway, but how to change the surface coordination of peroxymonosulfate (PMS), thereby affecting the catalytic mechanism of PMS, is still an unknown field. In this, we found that MIL-101(Fe) is expected to control the surface catalytic pathway via the bidentate binuclear coordination configuration, thereby realizing the rapid oxidative detoxification of toxic organic pollutants and CO₂ conversion. Introducing Cu on the surface of MIL-101(Fe) to change the surface chemical environment (MIL-101(Fe)/CuFeO_x) can shift the catalytic pathway, thereby promoting a 14.5-fold improvement in Bisphenol A (BPA) oxidation kinetics (from 0.00697 min⁻¹ to 0.101 min⁻¹). Characterization, experiments, and density functional theory (DFT) results show that Cu in the vicinity of Fe can tune the electronic structure and properties of Fe-O-Cu, thereby enhancing the electron transfer rate at the active center, facilitating electronic transitions and PMS adsorption. More importantly, shifting the binding configuration of PMS from monodentate mononuclear coordination on a single Fe center to bidentate binuclear coordination on Fe/Cu centers, shorter distance coordination structures and OO pulling of PMS. The effect promoted PMS cleavage to generate more ROS and changed the catalytic pathway from the radical pathway to the ¹O₂ and high-valent metal species pathway. The free radical/non-radical pathway co-mediated by ¹O₂, high-valent metal species, ·OH and SO₄^·− can effectively reduce the biotoxicity of toxic organic pollutants, and can utilize alkali environment captures CO₂ as a stable carbonate for environmental use. This study provides a strategy for manipulating the catalytic pathway through coordination configuration and a feasible idea for CO₂ conversion in wastewater treatment.