Catalytic Activation of Molecular Oxygen Toward Producing Hydroxyl Radicals Controllably for Highly Selective Oxidation of Hydroxyl Compounds under Mild Conditions

Hydroxyl radicals (OH•), as one of the most highly oxidizing oxidants, are difficult to utilize in chemical synthesis since they usually cause unavoidable oxidative damage with CO2 released. Here, a Co–N–C nanomaterial composed of CoN4 sites on graphitic carbon nitride was constructed, which fulfills the self-cascade activation of O2 in water, wherein OH• is guided to generate in a controlled level and exerts a highly selective oxidation role for efficient synthesis of a variety of organic acids by oxidation of furan alcohols, aromatic alcohols, and fatty alcohols under mild conditions. 5-Hydroxymethylfurfural (HMF) reached >99.9% conversion with 94.2% yield of 2,5-furandicarboxylic acid (FDCA) at 25 °C under atmospheric O2 pressure. This study allows a promising utility of O2 in a low energy-consuming way independent of light or electricity.