Boosting micropollutants removal over bimetallic Fe-Mo catalyst via peracetic acid activation: Mo doping enhanced generation of reactive oxygen species

Abstract

Herein, a range of bimetallic Fe-Mo catalysts (Fe_xMo_y@C) were successfully synthesized to explore the effect of Mo doping on the activity of Fe-based catalyst (Fe@C) for peracetic acid (PAA) activation. Mo doped during Fe@C preparation process introduced more low-valent metal species into Fe@C with the potential to promote PAA activation and Fe(III)/Fe(II) cycling. Compared to single Fe catalyst, Fe₄Mo₁@C exhibited outstanding performance in PAA activation for ultrafast degradation of bisphenol A (BPA), with the degradation rate of 0.88 min^-1, which exceeded most reported heterogeneous catalysts. Mechanism results indicated that the Mo doping promoted the generation of reactive species and accelerated Fe(III)/Fe(II) conversion on the surface of Fe₄Mo₁@C to ensure the continuous PAA activation. Further analysis revealed that incorporated Mo not only promoted electron transfer and accelerated transform of Fe(III) to Fe(II), but also lowered the energy barrier for PAA activation. Moreover, the toxicity of BPA and its intermediates could be effectively reduced in Fe₄Mo₁@C/PAA system, guaranteeing the safety of treatment process. This study clarified the mechanism of Mo doping to enhance the Fe-based catalysts activity for organic micropollutant degradation, and the new insights obtained would further promote the application of bimetallic catalysts in PAA-based advanced oxidation processes.