Highly Efficient Oxidation of N, N-Dimethylformamide at Low Temperature over a Mn-based Catalyst by Optimization Support

Abstract

The evaluation of catalytic oxidation of nitrogenous volatile organic compounds (NVOCs) relies on two key indicators: activity and N₂ selectivity. In this work, three different supports (SiO₂, ZSM-5 and Al₂O₃) loading with Mn or Mn-Ce were synthesized by deposition-precipitation for catalytic combustion of N, N-Dimethylformamide (DMF). Mn-Ce/ZSM-5 catalyst displayed the best performance for DMF oxidation, achieving 100% DMF conversion and CO₂ selectivity at 240 °C as well as 90% N₂ selectivity at 400 °C. It also exhibits excellent water resistance and high stability. All the characterization results indicated that the state of Mn species was positively correlated with catalytic activity. The addition of Ce species weakened the inhibitory interaction between Mn species and Al species, resulting in an elevation in the state of Mn species which was highest of the six catalysts, thus increasing activity. Meanwhile, the rise in surface oxygen species resulted in high CO₂ selectivity and rapid oxidation of NH₃. Furthermore, Bronsted acid sites on ZSM-5 facilitated NH₃-SCR progress, achieving a high N₂ selectivity at high temperatures.