Engineering surface defects and metal–support interactions on Pt/TiO2(B) nanobelts to boost the catalytic oxidation of CO

Herein, we report the high performance of thermally reduced Pt/TiO2(B) catalysts for the catalytic oxidation of CO. Our findings show that through hydrogen spillover from Pt to TiO2, surface-engineered defects of oxygen vacancies are "constructed" on the TiO2 support during the reduction process, thus generating active surface-adsorbed oxygen species. With an increase of the reduction temperature, the TiO2(B) phase gradually transforms to the anatase phase, which takes place from the bulk to the surface of TiO2, and is eventually completed at 700 degrees C. Compared with the anatase phase, the oxygen vacancies are more easily formed on the TiO2(B) phase, and the latter has much stronger interactions with Pt, as well. As the reduction temperature increases, the metal-support interaction between Pt and TiO2(B) is strengthened. Meanwhile, we simultaneously observe an increase in the dispersion of Pt, the proportion of Pt-0 and the adsorbed oxygen species on the surface. Our findings reveal that for thermally reduced Pt/TiO2 catalysts, surface-adsorbed oxygen and Pt-0 are active species for the catalytic oxidation of CO. Among the thermally reduced catalysts, H-600 shows the highest catalytic activity because it has the largest amount of active Pt-0 sites and surface-adsorbed oxygen species. In addition, it shows high water vapor resistance.