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.
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..