Synergistic effect of F and triggered oxygen vacancies over F-TiO on enhancing NO ozonation.

Oxidation-absorption technology is a key step for NO removal from low-temperature gas. Under the condition of low O concentration (O/NO molar ratio = 0.6), F-TiO (F-TiO), 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-TiO samples was higher than that of TiO (about 43.7%), and the NO oxidation efficiency of F-TiO-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-TiO, which could accelerate the transformation of monomolecular O into multi-molecule singlet oxygen (O), thus promoting the selective oxidation of NO to NO. The oxidation reaction of NO on F-TiO-0.15 follows the Eley-Rideal mechanism, that is, gaseous NO reacts with adsorbed O and finally form NO.