Photocatalytic Oxidation of Toluene on Fluorine Doped TiO₂/SiO₂ Catalyst Under Simulant Sunlight in a Flat Reactor

• Main Authors: Lu Qiu, Yanan Wang, Hanlinag Li, Gang Cao, Feng Ouyang, Rongshu Zhu
• Format: Article
• Language: English
• Published: MDPI AG 2018-12-01
• Series: Catalysts
• Subjects: photocatalysis; toluene; oxidation; titanium dioxide; fluorine; reactor
• Online Access: https://www.mdpi.com/2073-4344/8/12/596

Improving the capacity of TiO₂ semiconductors for visible light response is a key problem for utilization of solar energy in photo-catalytic degradation of organic pollutants. Both catalyst character and reactor conditions are important for the reaction efficiency. The fluorine ion doped TiO₂/SiO₂ catalyst was prepared by sol-gel method using HF solution as fluorine source. The activity test and UV⁻vis results indicated that this catalyst was superior to TiO₂ P25 in photocatalytic oxidation of gaseous toluene under simulant sunlight irradiation due to the enhancement of visible and ultraviolet light absorbance. GC-MS results indicated that the main intermediates accumulated on active sites included benzoic acid, benzaldehyde, and phenol. A flat interlaid reactor was designed for continuous treatment of the stream with F-TiO₂/SiO₂ film. The results showed that coating the catalyst on the surface of both top and bottom glass substrates, through the knife coating method with an optimal reactor height, attained the highest efficiency. In addition, the presence of water and oxygen enhanced the oxidation of toluene due to the generation of hydroxyl radicals and peroxy radicals, respectively. The toluene oxidation rate increased with the increase in water vapor concentration in the range of 0~60 vol.%.