Sol–gel encapsulation of Au nanoparticles in hybrid silica improves gold oxidation catalysis

Rosaria Ciriminna, Valerica Pandarus, Riccardo Delisi, Antonino Scurria, Maria Pia Casaletto, Francesco Giordano, François Béland, Mario Pagliaro

The introduction of an heterogeneously catalyzed gold-based alcohol oxidation process of broad applicability using a clean primary oxidant would be highly desirable. Gold is non toxic and carbonyl and carboxyl compounds are widely used to produce medicines, plastics, colorants, paints, detergents, fragrances, flavors, and other valued functional products. The sol-gel entrapment of gold nanoparticles in hybrid silica improves gold-based oxidation catalysis applied to the selective oxidation of alcohols with aqueous hydrogen peroxide as eco-friendly primary oxidant. Pronounced physical and chemical stabilization of the sol-gel entrapped Au nanoparticles is reflected in catalyst recyclability. Potential implications of these findings are significant, especially considering that the highly stable, mesoporous glassy catalyst is ideally suited for application in microreactors for carrying out the reaction under flow. Graphical abstractSelective oxidation of 2-phenylethanol over SiliaCat Au nanoparticle. Hydrogen peroxide is the clean oxidant.