The action mechanism of ethanol in preparation of supported nano-sized Ru catalyst via supercritical fluid deposition

• The Ru particle size has reached 1.7 nm, which is scarcely reported in other articles.
• Ru particle size can be effectively controlled by changing the amount of ethanol.
• The action mechanism of ethanol in SFD is firstly investigated systematically.
• The catalytic activity of Ru/C prepared by SFD-ethanol is higher than other catalyst.

Ru catalysts supported on activated carbon (AC) were prepared by supercritical fluid deposition (SFD) with ethanol added and their catalytic performance in butanone hydrogenation was investigated. The effects of ethanol amount on Ru particle size were systematically studied. As the amount of ethanol increased, Ru mean particle sizes always decreased firstly, then increased. And the minimum mean particle size of Ru was obtained at 10 ml ethanol. The catalysts with smaller Ru mean particle size presented higher catalytic activity. These results demonstrated that the role of ethanol may not be only co-solvent but also anti-solvent and extractant during the preparation of Ru/AC.