Mechanism for airborne ozone decomposition on X-MIL-53(Fe) (X = H, NH, NO).

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