Mesoporous Silicon-Carbon Composites: Novel Supports of Platinum Nanoparticles for Highly Efficient Selective Oxidation of Glycerol

Abstract

Selective oxidation of glycerol is an extremely challenging reaction because of that three hydroxyl groups in glycerol are prone to randomly oxidize, resulting in unsatisfactory selectivity. In this work, silicon-carbon composites (Si-C-n) were designed and prepared as novel supports for nano Pt catalyst to boost the activity and selectivity in oxidation of glycerol to glyceric acid (GLYA). By the tannic acid/silicic acid self-assembly and carbonization process, mesoporous Si-C-n microspheres with high surface area and controllable Si content were obtained. After the Pt loading, the as-prepared catalysts Pt/Si-C-3 exhibited significant enhanced glycerol conversion (74.4%) and exceptional GLYA selectivity (86.7%) compared with those of control catalysts Pt/SiC, Pt/SiO2, and Pt/CTA. It also showed excellent stability, experiencing no obvious performance loss after six cycles. The results of experiments and characterizations demonstrated that the unique composition structure of high surface area, moderate acidity and the strong interaction between Pt NPs and Si-C-3 may account for the good catalytic performance of Pt/Si-C-3.

Keywords: porous material, silicon-carbon composite, silicon carbide, selective oxidation, Pt nanoparticles