Heterogeneous activation of peroxymonosulfate by SBA-15 supported Co-based bimetallic catalysts for unsymmetrical dimethylhydrazine degradation in water

A set of SBA-15 supported Co-based bimetallic catalysts was prepared by the incipient wetness impregnation method and then used to activate peroxymonosulfate (PMS) to eliminate unsymmetrical dimethylhydrazine (UDMH). The physicochemical properties of catalysts were studied by serious of techniques. The reusability of the catalyst and the influence of reaction parameters were investigated. The results showed that AgCo/SBA-15 exhibited the best degradation efficiency. The good conductivity of Ag nanoparticles, strong UDMH adsorption ability, moderate Co ions leaching concentration, and the synergistic effect between Co and Ag were responsible for the excellent catalytic activity. Complete UDMH (100 mg/L) degradation and 75.2 % mineralization could be achieved at the reaction times of 15 and 180 min, respectively. The quenching experiments and EPR analysis indicated 1O2 played a dominant role in UDMH degradation. Furthermore, the possible degradation pathways were proposed according to the GC-MS intermediates and DFT calculation. This study provides new insights into heterogeneous activation of PMS and offers an efficient method for wastewater treatment.