A metal-/additive-free system for oxygen-mediated hydroxylation of benzene over polyfuran-functionalized hydrothermal carbocatalyst.

• A hydrothermal carbon with oxygen groups and polyfuran units was constructed. • The catalyst was efficient in metal-additive-free oxygen-mediated benzene to phenol. • Surface oxygen groups as the active sites to form ·OH radials to oxidize benzene. • The polyfuran units promoted the O 2 adsorption and activation to accelerate reaction. Direct benzene hydroxylation with dioxygen (O 2) is among the most promising alternative pathways for green phenol production, but efficient catalysis systems usually involve metal species or other additives such as sacrificial agents. In this work, we designed a carbon catalyst from the hydrothermal treatment of biomass-derived sucrose and constructed a metal-/additive free heterogeneous catalytic system for benzene hydroxylation to phenol with O 2. The champion carbon sample gave a high phenol yield of 13.4%. The catalyst was facilely recovered and reused without apparent deactivation. There abundant oxygen functional groups such as phenolic and quinone carbonyl groups served as the active sites and polyfuran units accelerated the O 2 adsorption and activation. The synergistic effect of these surficial organic groups is conducive to the formation of reactive oxygen species, hydroxyl radicals, which effectively oxidized the benzene to phenol. Sucrose-derived hydrothermal carbon material with abundant polyfuran units allowed the efficient metal- and additive-free benzene hydroxylation to phenol with O 2. [Display omitted] [ABSTRACT FROM AUTHOR]