Visible light-driven selective oxidative transformation of vicinal diols using ZnS-based photocatalyst in the presence of molecular oxygen

• Published in: Green chemical engineering 2024-11
• Main Authors: Liu, Ruichen, Wang, Miao, Zheng, Jiaxin, Tong, Xinli
• Format: Article
• Language: English
• Subjects: Benzaldehyde; Molecular oxygen; Photocatalysis; Selective oxidation; Visible light
• ISSN: 2666-9528; 2666-9528
• DOI: 10.1016/j.gce.2024.11.002

The heterogeneous photocatalysis for the oxidative cleavage of C–C bond is significant to the transformation of biomass feedstock. In this work, a heterojunction photocatalyst based on the conductor ZnS and C3N4 (CN) material is prepared and employed in the aerobic oxidative cleavage reaction of vicinal diol under visible light irradiation. As a result, it is found that 3ZnS/CN catalyst obtained by a mechanical grinding method shows a high photocatalytic activity. In the photocatalytic oxidative cleavage process of 1-phenyl-1,2-glycol, more than 98.7% conversion of substrate with a 96.2% selectivity of benzaldehyde was attained using O2 as oxidant. In addition, the photocatalyst recycling experiments exhibited that the 3ZnS/CN catalyst still kept a good activity and stability even after being recycled for 5 times. Finally, the active reaction intermediates were investigated by the control experiments and the relative electron paramagnetic resonance (EPR) detection. According to the obtained results and photocatalytic principle, the mechanism for the selective oxidative transformatioin of 1-phenyl-1,2-glycol has been proposed. It gives a promising approach for the catalytic utilization of biomass-based lignin and cellulose. A visible light-driven selective oxidative C–C bond cleavage process is developed with 3ZnS/CN as the photocatalyst in the presence of molecular oxygen. [Display omitted] •An aerobic oxidative cleavage process of vicinal diols is achieved.•The ZnS/CN heterojunction was used as the photocatalyst.•94.9%–97.0% yields of corresponding aromatic aldehydes were obtained.•A possible reaction mechanism for oxidation of vicinal diol is proposed.