The Effect of Hydrogenated TiO2 to the Au/TiO2 Catalyst in Catalyzing CO Oxidation.

ABSTRACT

Supported Au catalysts are widely used for CO oxidation due to their extremely high activity, and the modification of a support structure is a crucial method to improve catalytic performance. Herein, we prepared gold catalysts supported on flaky TiO2 and on TiO2 hydrogenated at different temperatures (200, 400, and 600 °C). We found that the sample with the support pretreated in hydrogen at 600 °C (0.5Au/TiO2-H600) showed the greatest advantages in activity and stability over the sample with as-prepared TiO2 nanosheets (0.5Au/TiO2-UC). First, calcination at 600 °C changed the exposed surface of TiO2 from {001} to {101}, and gold nanoparticles (2-3 nm) were observed as highly reactive species on 0.5Au/TiO2-H600. Moreover, the increase of oxygen vacancies on the surface of 0.5Au/TiO2-H600 was conducive to oxygen activation and promoted the catalytic activity. Therefore, we emphasized the important role of the support and gave an effective method to improve the catalytic performance by regulating the support structure.