Selective oxidation of alcohols to high value-added carbonyl compounds using air over Co-Co 3 O 4 @NC catalysts

The sustainable catalytic transformation of alcohols to high value-added fine chemicals is a significant and challenging research topic. Herein, a set of nitrogen-doped carbon encapsulated Co-based catalysts (Co-Co 3 O 4 @NC-T) were prepared by using low-cost dicyandiamide, glyoxal and cobalt nitrate as precursors. The obtained catalysts were utilized for the selective oxidation of alcohols to high value-added esters and carboxylic acids with air as the oxygen source and displayed wide applicability for the oxidation of both aromatic and aliphatic alcohols. Based on the controlled experiments, the protective effect of N-doped carbon structure and the synergistic effect between Co core and Co 3 O 4 species guaranteed the high reaction conversion and selectivity. Benefitting from heterogeneity and magnetism of the catalyst, it can be easily recycled and reused for long-term stability. Reasonable mechanisms of selective oxidation reaction were proposed through EPR analysis and controlled experiments. The present work provides a facile strategy for potential large-scale preparation of heterogeneous catalyst for sustainable and green catalytic transformations.