Preparation of graphene supported copper composite materials and study on the catalytic activity of phenol hydroxylation

Abstract

The hydroxylation of phenol to synthesize dihydroxybenzene (DHB) has recently attracted considerable attention due to its inherent advantages, including its simplicity in industrial applications, environmental friendliness, and remarkable selectivity towards DHB. The hydrothermal method was used to prepare graphene supported copper composites (Cu/GNS) with excellent catalytic properties, which were applied in the phenol hydroxylation for DHB preparation. Cu/GNS with controllable copper content were successfully obtained, achieving the homogeneous dispersion of copper ions on the graphene surface while preventing graphene agglomeration. During catalysis, graphene serves as an electron transport conduit, enhancing the exposure of reactive active sites and facilitating the generation of hydroxyl radicals. The π-π interactions between graphene and phenol enhance the propensity for collision between phenol and hydroxyl radicals. The total selectivity of DHB reached 98.4%, and the phenol conversion reached 85.1%. The composites exhibited high stability, with 80.5% phenol conversion and 93.7% DHB total selectivity even after five reuse cycles.