Room temperature synthesis of reduced TiO2 and its application as a support for catalytic hydrogenation

Abstract

Reduced TiO₂ (TiO_2−x) materials have attracted increasing attention due to their large solar absorption and high photo-activity. However, their synthesis procedures usually involve harsh conditions, such as high temperature and/or high pressure. Herein, a facile solid ball-milling method for the synthesis of TiO_2−x under ambient conditions was developed. By using finely dispersed Na/NaCl powders as the reducing agent and TiO₂ (P25, Degussa) as the precursor, a series of TiO_2−x of 20–30 nm with a controllable reduction degree can be successfully synthesized through adjusting the reaction conditions. The surface area of TiO_2−x is much larger than that of pristine TiO₂, showing its great potential as a catalyst support in chemical reactions. Our experimental results show that uniform Ru particles with particle size less than 1 nm can be well dispersed on the surface of the TiO_2−x due to the enhanced surface area and plenty of oxygen vacancies in TiO_2−x. As a result, Ru/TiO_2−x exhibited superior activity upon catalytic hydrogenation of N-methylpyrrole in comparison with Ru/TiO₂.