Synergistic effect of F and triggered oxygen vacancies over F-TiO2 on enhancing NO ozonation
Qin Zhong , Lina Guo , Xu Zhang , Fanyu Meng , Jing Yuan , Yiqing Zeng , Chenyang Han , Yong Jia , Mingyan Gu , Shule Zhang
DOI:10.1016/j.jes.2022.01.006
Received August 23, 2021,Revised , Accepted January 05, 2022, Available online January 12, 2022
Volume 35,2023,Pages 319-331
Oxidation-absorption technology is a key step for NOx removal from low-temperature gas. Under the condition of low O3 concentration (O3/NO molar ratio = 0.6), F-TiO2 (F-TiO2), which is cheap and environmentally friendly, has been prepared as ozonation catalysts for NO oxidation. Catalytic activity tests performed at 120°C showed that the NO oxidation efficiency of F-TiO2 samples was higher than that of TiO2 (about 43.7%), and the NO oxidation efficiency of F-TiO2-0.15 was the highest, which was 65.3%. Combined with physicochemical characteristics of catalysts and the analysis of active species, it was found that there was a synergistic effect between F sites and oxygen vacancies on F-TiO2, which could accelerate the transformation of monomolecular O3 into multi-molecule singlet oxygen (1O2), thus promoting the selective oxidation of NO to NO2. The oxidation reaction of NO on F-TiO2-0.15 follows the Eley-Rideal mechanism, that is, gaseous NO reacts with adsorbed O3 and finally form NO2.
