Abstract Heterogeneous photocatalysis with TiO2 have been studied for VOCs degradation; however, aromatic VOCs degradation lead TiO2 deactivation. The objective of this study was to degrade aromatic VOCs by heterogeneous photocatalysis avoiding TiO2 deactivation. The experiments were conducted using a UV-C lamp (254 nm), relatively humidity (RH – 26–60 %), and ozone (O3 – 2.38 to 5.35 %). Due to O3 addition, it was necessary to have uncoated regions in the quartz tube around the lamp to allow UV photons to reach the gas bulk and generate radicals from O3. Different quartz tube coating fractions were tested to analyze its influence on VOCs degradation. The highest toluene degradation was 99.2 % for the reactor with 90 % of coating, 3.4 % of O3, space time of 123 s, and RH of 26 %. It was observed RH greater than 26 % affected the degradation achieved. Ozone addition allowed TiO2 use for 77 h avoiding early catalyst deactivation. Besides that, the requirement of uncoated regions indicated that VOC oxidative reactions occur both on solid and gas phases. This suggested that the addition of O3 combined with the reactor configuration is a promising alternative for aromatic compound degradation by heterogeneous photocatalysis.

中文翻译：

---

部分 TiO2 涂覆的光反应器在臭氧辅助下降解气相芳香族化合物

摘要 研究了 TiO2 的多相光催化降解 VOCs；然而，芳香族 VOC 的降解导致 TiO2 失活。本研究的目的是通过多相光催化降解芳香族 VOC，避免 TiO2 失活。实验使用 UV-C 灯 (254 nm)、相对湿度 (RH – 26–60 %) 和臭氧 (O3 – 2.38 至 5.35 %) 进行。由于 O3 添加，必须在灯周围的石英管中有未涂层区域，以允许 UV 光子到达气体主体并从 O3 中产生自由基。测试了不同的石英管涂层组分，以分析其对 VOC 降解的影响。对于具有 90% 涂层、3.4% O3、123 s 时空和 26% RH 的反应器，甲苯降解率最高为 99.2%。据观察，大于 26% 的 RH 会影响实现的降解。添加臭氧允许 TiO2 使用 77 小时，避免催化剂过早失活。除此之外，未涂层区域的要求表明 VOC 氧化反应发生在固相和气相上。这表明添加 O3 与反应器配置相结合是通过多相光催化降解芳香族化合物的有希望的替代方案。