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

Abstract

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 °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 Pt⁰ and the adsorbed oxygen species on the surface. Our findings reveal that for thermally reduced Pt/TiO₂ catalysts, surface-adsorbed oxygen and Pt⁰ 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 Pt⁰ sites and surface-adsorbed oxygen species. In addition, it shows high water vapor resistance.