Covalent triazine framework @ silica core-shell spheres decorated with ultrafine platinum nanoparticles: a robust catalyst for selective aqueous phase hydrogenation of butane-2,3-dione and pyruvic acid

Abstract

Sub-nanometric sized Pt nanoparticles, generated by metal vapor synthesis technique, were supported onto covalent triazine framework @ silica (CTF@SiO2) core-shell hybrid microspheres obtained through polycondensation reactions at the SiO2 surface. The later catalyst and a reference system (i.e. Pt nanoparticles deposited onto bare SiO2 microspheres) were screened under identical experimental conditions in the hydrogenation of butane-2,3-dione and pyruvic acid in water, leading to butane-2,3-diol and lactic acid in high selectivity. A combination of catalytic recycling experiments was conducted with both catalysts, along with transmission electron microscopy and X-ray diffraction analyses performed on either as-synthesized and recovered catalysts confirmed the remarkable role of the CTF shell layer on the stabilization of ultrafine Pt NPs against their aggregation under catalysis as well as on its catalytic activity.