Different degradation mechanisms of low-concentration ozone for MIL-100(Fe) and MIL-100(Mn) over wide humidity fluctuation.
Different degradation mechanisms of low-concentration ozone for MIL-100(Fe) and MIL-100(Mn) over wide humidity fluctuation.
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DOI：
10.2139/ssrn.4147029
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发表时间：
2022-09
期刊：
影响因子：
8.8
通讯作者：
Guanqing Song;Gansheng Shi;Lu Chen;Xiao Wang;Jing Sun;Lei Yu;Xiao Xie
中科院分区：
文献类型：
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作者：
Guanqing Song;Gansheng Shi;Lu Chen;Xiao Wang;Jing Sun;Lei Yu;Xiao Xie
臭氧与细颗粒物的协同控制是当前环境领域的研究热点。在臭氧去除中，大范围的湿度波动和低浓度的动态吸附是两个棘手的问题。本论文选择水热法和溶剂热法合成的MIL-100（Fe）和MIL-100（Mn）作为催化剂，研究了它们对流动臭氧污染物的降解作用。样品表现出不同的臭氧降解机理，即光催化降解和常温降解。MIL-100（Fe）的光催化活性明显高于MIL-100（Mn），而MIL-100（Mn）的常温催化效率远高于MIL-100（Fe）的上级催化效率。对于不同的湿度条件，MIL-100（Fe）在10%湿度下具有最佳的光催化性能，为38%，而MIL-100（Mn）在10- 90%的不同湿度水平下常温催化降解效率基本没有变化。通过原位漫反射红外光谱和电子顺磁共振谱分析，提出了薄膜的光致降解机理，认为薄膜的光致降解与氧空位和光生电子效率密切相关。通过程序升温脱附（TPD）分析，发现MIL-100（Mn）中存在大量的刘易斯酸中心，这是所选材料在高湿环境下仍能保持良好常温降解性能的关键因素。本工作将拓展臭氧去除的实际应用，提高降解效率。
The synergistic control of ozone and fine particulate matter is a research hotspot in the current environmental fields. Among the ozone removal, wide humidity fluctuation and low concentration dynamic adsorption are two thorny problems. In this work, MIL-100(Fe) and MIL-100(Mn), synthesized by hydrothermal and solvothermal methods respectively, were selected to investigate the degradation of flowing ozone pollutants. The samples showed different ozone degradation mechanisms, namely photocatalytic degradation and normal temperature degradation. Notably, MIL-100(Fe) exhibited more outstanding photocatalytic activity than MIL-100(Mn), while the normal temperature catalytic efficiency of MIL-100(Mn) was much superior to MIL-100(Fe). For different humidity conditions, MIL-100(Fe) has the optimal photocatalytic performance at 10% humidity, which is 38%, while MIL-100(Mn) has basically no change in normal temperature catalytic degradation efficiency at different humidity levels of 10-90%. Furthermore, the degradation mechanism was proposed by in-situ DRIFTS and ESR, which was significantly correlated with oxygen vacancy and photogenerated electron efficiency. By the aid of Temperature Programmed Desorption (TPD), a large quantity of Lewis acid sites was detected in MIL-100(Mn), which was the critical factor that the selected materials could maintain excellent normal temperature degradation performance under high humidity. This work will expand the practical application of ozone removal and improve the degradation efficiency.