Mechanism for airborne ozone decomposition on X-MIL-53(Fe) (X = H, NH2, NO2)

Ground−level ozone (O 3 ) pollution poses a significant threat to both ecosystem sustainability and human health. The catalytic decomposition of O 3 presents as a promising technology to address the issues of O 3 pollution. This study undertook the synthesis of various functionalized metal−organic framework (MOF) catalysts ( i.e., X-MIL-53(Fe) (X = H, NH 2 , NO 3 )) to delve into the influence of ligand functional groups on skeletal structure and catalytic efficacy, particularly focusing on unraveling the mechanism of O 3 catalytic decomposition under humid conditions. NH 2 -MIL-53(Fe) catalyst achieved complete O 3 decomposition under ambient temperature and high humidity conditions (RH=75 %), exhibiting a reaction rates (mol·m −2 ·s −1 ) 129 and 10.5 times greater than that of MIL-53(Fe) and NO 2 -MIL-53(Fe). The NH 2 group promotes electron flow within the backbone towards the hydroxyl group (OH) linked to Fe atom. In humid O 3 , H 2 O molecules augment the interaction between O 3 and NH 2 -MIL-53(Fe), and OH is converted to·O 2 − after deprotonation, promoting O 3 decomposition. Additionally, leveraging three−dimensional (3D) printing technology, a monolithic catalyst for O 3 decomposition was prepared for application. This study not only advances understanding of the mechanisms underlying O 3 decomposition but also offers practical solutions for addressing O 3 pollution at humid conditions.