Preparation of platinum nanoparticles supported on bayberry tannin grafted silica bead and its catalytic properties in hydrogenation

Bayberry tannin (BT), a natural plant polyphenol, was used as a stabilizer to prepare supported platinum catalysts. Bayberry tannin was first grafted onto aminated SiO 2 beads and subsequently coordinate with Pt(IV) species. Then a series of heterogeneous Pt–bayberry tannin–SiO 2 (Pt–BT–SiO 2 ) catalysts was obtained after reduction with NaBH 4 . The catalysts were characterized by UV–DR, XRD and TEM, and the coordination state of Pt(IV) with BT grafted on SiO 2 beads was investigated by XPS. It was found that the Pt–BT–SiO 2 catalysts were highly active and stable in aqueous hydrogenation of acrylic acid, α-methacrylic acid, allyl alcohol and 2-methyl-3-buten-2-ol. Moreover, the Pt–BT–SiO 2 catalysts could be conveniently recovered from the reaction systems simply by filtration, and be reused at least five times without loss of activity.