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·H2O, the aromatic alcohols were successfully converted to the corresponding aromatic acids or aromatic nitriles, respectively. Experimental and theoretical studies confirmed that the Co–N4 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.