Enhanced stability and activity of Mn single atom decorated γ-AlOOH towards perfluorooctanoic acid removal via catalytic ozonation

Catalytic ozonation offers a promising approach for removing perfluorinated compounds, yet developing catalysts with both high activity and stability remains a great challenge due to severe metal ions leaching. Herein, we design a Mn single atom decorated γ-AlOOH catalyst (denoted as Mn x /γ-AlOOH), which displays efficient catalytic ozonation towards perfluorooctanoic acid (PFOA) removal. Under optimal conditions, Mn 2.2 /γ-AlOOH achieves a defluorination ratio of 99.39% after 15 h of catalytic ozonation process, with a distinctive low leaching percentage (0.52% for Mn and 0.21% for Al, compared to 10.44% for Mn leaching from MnO 2 and 0.95% for Al leaching from γ-AlOOH). Comprehensive analysis indicates that the introduction of Mn single atom optimizes the electronic structure and provides an additional indirect electron transfer pathway, which not only facilitates O 3 activation, but also reduces Mn ion leaching by decreasing electron loss, and simultaneously enhances the activity and stability of the catalyst. This work provides new insights into enhancing the activity and stability of catalysts during the catalytic ozonation process via the rational design of atomically dispersed sites.