Solvated gold atoms in the preparation of efficient supported catalysts: Correlation between morphological features and catalytic activity in the hydrosilylation of 1-hexyne

摘要

In the last 20 years, nanostructured gold species have received increasing attention due to their activity in many reactions such as selective oxidations and reductions of fine organic chemicals, both in gas phase and in liquid phase. Here, we report that gold nanoparticles prepared from Au/CH_3COCH_3 solution (obtained from gold vapours and acetone by the Metal Vapour Synthesis technique) can be directly deposited on a wide series of different supports (C, Al_2O_3, Fe_2O_3, CeO_2, TiO_2 and ZrO_2) with their small dimensions being maintained. The supported gold nanoclusters thus obtained are effective catalysts for the hydrosilylation of acetylenic compounds. The catalytic performance of Au is defined by two major factors: particle size and choice of support. For instance, the results obtained from the reaction of 1-hexyne with triethylsilane in the presence of Au/γ-Al_2O_3 (0.05 mol%) demonstrate the high selectivity and the excellent specific activities typical of these gold catalysts.