Authors: Kolobova, E; Pakrieva, E; Pascual, L; Corberan, VC; Bogdanchikova, N; Farias, M; Pestryakov, A

Article; Proceedings Paper.
Catal. Today. vol: 333. page: 0920-5861.
Date: AUG 1. 2019.
Doi: 10.1016/j.cattod.2018.04.046.

We investigated the influence of metal loading in gold catalysts supported on titania, either unmodified or Lamodified, on their catalytic performance and the formation of active sites for selective oxidation of n-octanol under mild conditions. Catalysts were characterized by BET, EDX, ICP, HRTEM, FTIR CO and XPS. Gold content had a significant effect on the catalytic properties of unmodified catalysts: activity of Au/TiO2 increased by increasing the metal load. However, in the case of a lanthanum-modified support samples, an increase of gold content from 0.5 to 4 wt.% had no effect on its activity (ca. 40% conversion after 6 h for all catalysts). This catalytic behavior is due to a change in the surface concentration of Au+ ions. For the unmodified catalysts, the surface concentration of Au+ ions increased with increasing gold loading, and, as a consequence, a significant increase in activity was observed. For La-modified catalysts, the surface concentration of Au+ ions is almost the same for all gold concentrations; as a result, no increase in activity was observed with the increase in gold content. It points to Au+ ions as the most probable active sites for the studied reaction..