Room Temperature HCHO Conversion using Oxygen Vacancy-Rich TiO2 Supported Noble Metal Catalyst

J. Jurng, W. Ahmad, Y. Oh
Korea Institute of Science and Technology,

Keywords: oxygen vacancy-rich TiO2, Pt nanoparticles, electronic metal-support interaction, electron transfer catalyst, room-temperature catalytic HCHO conversion


Catalytic oxidation of HCHO at room temperature using noble metal catalysts is an efficient strategy for indoor air purification. However, the optimization of catalytic oxidation through support defect control has not been extensively studied. In this study, we developed an electron transfer catalyst support based on oxygen vacancy-rich anatase TiO2 (VO-TiO2) for efficient HCHO conversion to CO2 and H2O. VO-TiO2 was prepared by chemical vapor condensation with post heat treatment, which resulted in void-embedded nanostructures and electron paramagnetic activity. These properties affected the deposition pattern of Pt nanoparticles upon impregnation. Pt/VO-TiO2 (0.086 wt% Pt) achieved 100% conversion of 10 ppm HCHO at room temperature and 200,000 cm3 h-1 gcat-1 GHSV in >250 min. The X-ray absorption studies of used catalysts confirmed the conservation of the metallic state of Pt only in oxygen vacancy-rich anatase TiO2 (VO-TiO2). First-principles density-functional theory calculations showed that excess electrons at the oxygen vacancies in VO-TiO2 stabilized the otherwise vulnerable Pt nanoparticles. This study highlights the effectiveness of defect control strategy for transforming TiO2 support into a dynamic electron transfer catalyst platform.