Oxygen vacancies enabled enhancement of catalytic property of Al reduced anatase TiO2 in the decomposition of high concentration ozone

Abstract The catalytic decomposition of gaseous ozone (O 3 ) is investigated using anatase TiO 2 (A-TiO 2 ) and Aluminum-reduced A-TiO 2 (ARA-TiO 2 ) at high concentration and high relative humidity (RH) without light illumination. Compared with the pristine A-TiO 2 , the ARA-TiO 2 sample possesses a unique crystalline core-amorphous shell structure. It is proved to be an excellent solar energy “capture” for solar thermal collectors due to lots of oxygen vacancies. The results indicate that the overall decomposition efficiency of O 3 without any light irradiation has been greatly improved from 4.8% on A-TiO 2 to 100% on ARA-TiO 2 under the RH=100% condition. The ozone conversion over T500/ARA-TiO 2 catalyst is still maintained at 95% after a 72 h test under the reaction condition of 18.5 g/m 3 ozone initial concentration, and RH=90%. The results can be explained that T500/ARA-TiO 2 possesses the largest amorphous contour, the lowest crystallinity, the most surface-active Ti 3+ /T i4+ couples, and the most oxygen vacancies. This result opens a new door to widen the application of TiO 2 in the thermal-catalytic field.