Atomically Dispersed Co on N-Doped Porous Carbon for the Highly Efficient Catalytic Oxidation of Aromatic Alcohols to Acids and Nitriles

An ecofriendly and facile strategy for converting aromatic alcohols to high-value-added compounds, especially acids and nitriles, is highly desirable. Herein, atomically dispersed Co species anchored on N-doped porous carbon were fabricated by simple one-pot pyrolysis using low-cost precursors. The as-obtained Co/NC catalyst with a high Co loading of 8.77 wt % exhibited excellent performance for the one-step oxidation of aromatic alcohols. Under ambient air reaction conditions and with the addition of KOH or NH3<middle dot>H2O, the aromatic alcohols were successfully converted to the corresponding aromatic acids or aromatic nitriles, respectively. Experimental and theoretical studies confirmed that the Co-N-4 sites serve as the primary active sites for the activation of aromatic alcohols. The transformation of aromatic alcohols to aldehydes is a crucial intermediate pathway. Density functional theory (DFT) calculations revealed that compared to the Co nanoparticle catalysts, the Co/NC catalyst with atomically dispersed active sites exhibited a lower energy barrier for the aerobic oxidation of benzyl alcohol to benzaldehyde. Additionally, the prepared single-atom Co/NC catalyst displayed remarkable recyclability and applicability. This study provides not only a potential strategy for constructing highly efficient non-noble metal catalysts but also a facile approach for the aerobic oxidation of aromatic alcohols to high-value-added products.