Selective surface modification of activated carbon for enhancing the catalytic performance in hydrogen peroxide production by hydroxylamine oxidation

Abstract

The textural structure and the surface property of activated carbon were selectively modified by KMnO 4 oxidation. The activated carbon treated by KMnO 4 oxidation in an acidic solution showed greatly enhanced H 2O 2 production by hydroxylamine oxidation due to the creation of more surface quinoid species, and the yield of hydrogen peroxide approached 78% (0.66 wt.%). Structure and surface analyses revealed that KMnO 4 oxidation in the acidic solution produced more phenolic but less carboxylic groups on the activated carbon, confirming the crucial role of the quinoid groups. It was further proposed that the quinoid groups serving as electron acceptors and redox mediators involved in the formation of H 2O 2 through a redox cycle.