Catalytic activity of gold nanoparticles deposited on N-doped carbon-based supports in oxidation of glucose and arabinose mixtures

Oxidation of a mixture of glucose and arabinose over Au particles deposited on porous carbons, N-doped carbons and carbon nitrides was investigated at 70 degrees C, under constant pH of 8, and oxygen partial pressure 0.125 atm. In particular, Au deposited on nitrogen-containing carbon-based mesoporous structures demonstrated activity in the oxidation of the sugars to the corresponding aldonic acids higher than gold deposited on undoped carbon supports (conversion of glucose up to ca. 60%, arabinose-ca. 30% after 200 min). The results can be explained by the basic nature of the supports leading to an increase in the polarity of the carbon surface and the oxygen activation. Glucuronic acid (with selectivity ca. 10-93.5%) together with gluconic acid was formed as a result of glucose oxidation, while arabinose was selectively oxidized to arabinonic acid.