Design of high-performance ozone catalysts by identifying and modulating anchoring sites for metal on γ-Al2O3 spheres

This study investigated the important role of hydroxyl groups for the preparation of γ-Al 2 O 3 sphere supported metal catalysts. γ-Al 2 O 3 spheres were calcinated at varied temperatures for the analysis of surface hydroxyl group, and they were subsequently loaded with iron to evaluate the metal dispersion and the performance for catalytic ozonation. The results showed that the critical site for metal anchoring was hydroxyl group, thus a higher hydroxyl group content favored the metal dispersion on γ-Al 2 O 3 spheres; meanwhile, the iron-loaded catalysts prepared by the γ-Al 2 O 3 support calcinated at 300 °C achieved the highest catalytic efficiency for p -nitrophenol degradation (74.6 %). The favorable performance of the catalyst was attributed to the excellent dispersion of iron oxide particles, and the abundant oxygen vacancy sites that facilitated the formation of ozone-activating sites, Fe-centered hydroxyl groups ([Fe-OH]). This study provides an important theoretical guidance for the design and application of ozone catalysts.