The nitric oxide ISO photocatalytic reactor system: Measurement of NOx removal activity and capacity
The nitric oxide ISO photocatalytic reactor system: Measurement of NOx removal activity and capacity
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DOI：
10.1016/j.jphotochem.2015.03.002
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发表时间：
2015-06-01
影响因子：
4.3
通讯作者：
Elouali, Sofia
中科院分区：
文献类型：
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作者：
Mills, Andrew;Elouali, Sofia
尽管基于 NO 去除的空气净化 ISO 方法 ISO 22197-1:2007 已十分成熟，但其预处理要求意味着仅测量被测光催化剂的初始活性，因为经常报道，通过表面 HNO3 的积累，空气氧化 NO 的表面动力学逐渐发生变化。在此，我们比较了表面饱和光生 HNO3 的多种不同常见 TiO2 材料的光催化 NO 去除能力，以及在典型的 5 小时长 ISO 标准测试中观察到的行为。研究发现，所有研究的 TiO2 材料在充分暴露于 NO 照射下（>5 小时）后，由于表面 HNO3 的积累，最终大部分变成 NO 到 NO2 转换器。对于每种不同的催化剂，达到 HNO3 饱和条件所需的 UV 暴露时间 t* 是不同的。因此，提出了 ISO 方法的替代预处理过程，该过程可用于提供对基础材料的光催化活性的更实际的测量，并提供对测试中的光催化材料的 NOx 去除能力的测量。 (C) 2015 Elsevier B.V. 保留所有权利。
Although the NO removal-based air-purification ISO method ISO 22197-1:2007 is well established, its preconditioning requirements mean that only the initial activity of the photocatalyst under test is measured owing to the often-reported, gradual alteration of the surface kinetics for NO oxidation by air through the accumulation of surface HNO3. Herein, we compare the photocatalytic NO removal abilities of a number of different, common TiO2 materials, surface-saturated with photogenerated HNO3, with their behaviours observed during the typical 5 h-long ISO standard test. It is found that all the TiO2 materials studied eventually become largely NO to NO2 converters after sufficient exposure to NO under irradiation (>5 h) due to the accumulation of surface HNO3. The UV exposure time, t*, necessary to reach this HNO3 saturated condition is different for each different catalyst. As a consequence, an alternative preconditioning process for the ISO method is proposed which can be used to provide a more realistic measure of the photocatalytic activity of the underlying material and provide a measure of the NOx removing capacity of the photocatalytic material under test. (C) 2015 Elsevier B.V. All rights reserved.