Silica supported silver nanoparticles from a silver(I) carboxylate: Highly active catalyst for regioselective hydrogenation

The selective hydrogenation of the α,β-unsaturated aldehyde citral (3,7-dimethyl-2,6-octadienal) was investigated with nano-sized silver particles on silica (Ag/SiO2). The catalysts were synthesized from the precursors silver nitrate and silver 2-[2-(2-methoxyethoxy)ethoxy]acetate [AgO2C(CH2OCH2)3H], respectively, and a mean particle diameter in the range of 4–8 nm could be detected via TEM. The results show that these catalysts are selective for CO hydrogenation of citral (SUOL = 71–77% at X = 50%) even at high conversion levels. In addition, the silver carboxylate [AgO2C(CH2OCH2)3H], soluble in water as well as in polar organic solvents, offers a straightforward preparation route for nano-sized silver particles generation.