Synthesis and Characterization of Nitrogen-Doped Carbon Nanospheres Decorated with Au Nanoparticles for the Liquid-Phase Oxidation of Glycerol

Abstract

Carbon and nitrogen-doped carbon nanospheres (CNS) were prepared by thermal pyrolysis of benzene (CNSB), aniline (CNSAN), and nitrobenzene (CNSNB) and used as supports for gold nanoparticles. Gold-based catalysts were prepared by the gold-sol method. The catalysts were checked in liquid-phase glycerol oxidation. The nature of the N-containing groups influenced both the acid–base properties of the supports and the Au particle deposition. As a consequence, an enhanced metal sintering by enriching the surface electron density of the support, essentially in the quaternary form, was observed. Both the glycerol conversion and glyceric acid selectivity increased with decreasing gold particle size. Moreover, catalyst Au/CNSB promoted the formation of glyceric acid, whereas Au/CNSAN and Au/CNSNB catalysts favored the oxidation of the secondary hydroxyl group of glycerol. Results clearly confirmed the influence of the support properties on the catalytic performance of gold in selective glycerol oxidation.