Constructed electron-dense Mn sites in nitrogen-doped Mn3O4 for efficient catalytic ozonation of pyrazines: Degradation and odor elimination

In this study, N-doped Mn3O4 catalysts (Mn-nN) with electron-dense Mn sites were synthesized and employed in heterogeneous catalytic ozonation (HCO). These catalysts demonstrated excellent performance in pyrazines degradation and odor elimination. The synthesis of Mn-nN was achieved through a facile urea-assisted heat treatment method. Experimental characterization and theoretical analyses revealed that the Mn-N structures in Mn-nN, played a crucial role in facilitating the formation of electron-dense Mn sites that served as the primary active sites for ozone activation. In particular, Mn-1N exhibited excellent performance in the HCO system, demonstrating the highest 2,5-dimethylpyrazine (2,5-DMP) degradation efficiency. center dot OH was confirmed as the primary reactive oxygen species involved in the HCO process. The second-order rate constants for 2,5-DMP degradation with O3 and center dot OH, were determined to be (3.75 +/- 0.018) x 10-1 and (6.29 +/- 0.844) x 109 M-1 s- 1 DMP via HCO process with Mn-1N. The degradation pathways were subsequently proposed by considering these identified intermediates. This study introduces a novel approach to synthesize N-doped Mn3O4 catalysts and demonstrates their efficacy in HCO for the degradation of pyrazines and the elimination of associated odors. The results show that the catalysts are promising for addressing odor-related environmental issues and provide valuable insights about the broader significance of catalytic ozonation processes. , respectively. Seventeen intermediates were identified through GC-MS analysis during the degradation of 2,5 -

Automated summary

In this study, N-doped Mn3O4 catalysts were synthesized and applied in heterogeneous catalytic ozonation. The Mn-N structures in the catalysts played a crucial role in facilitating the formation of electron-dense Mn sites, which served as the primary active sites for ozone activation. The catalysts demonstrated excellent performance in pyrazines degradation and odor elimination.