Selective oxidation of glycerol with oxygen in base-free solution over N-doped-carbon-supported Sb@PtSb2 hybrid

Abstract

Selective oxidation of glycerol with molecular oxygen in base-free aqueous solutions has become a hot topic, as the rapidly increasing production of biodiesel is creating a surplus of glycerol. In this work, an N-doped-carbon-supported core-shell structured Sb@PtSb2 hybrid catalyst was prepared via a facile synthesis route, in which a mixture of glucose, melamine, and SbCl3 (Sb-NC) was pyrolyzed, then impregnated with Pt by immersion in an aqueous solution of H2PtCl6, and further treated in hydrogen flow. Characterization of the catalyst products indicated that introducing SbCl3 can increase the surface area of the binary glucose + melamine pyrolyzed support (NC), and Sb@PtSb2 hybrids could be formed on the surface of an Sb-NC support during hydrogen treatment at 700 °C. It was found that the Sb@PtSb2/NC catalyst was more active for the selective oxidation of glycerol in a base-free aqueous solution than Sb-free NC-supported Pt (Pt/NC). Further characterization also indicated that the promising performance of Sb@PtSb2/NC might be attributed to its enhanced oxygen activation.