Investigation into the role of MoS2 in the composite of Cu-Cu2O/MoS2 in catalytic aerobic oxidation of benzylic alcohols

• Published in: Applied surface science Vol. 679; p. 161144
• Main Authors: Pei, Yi, Zheng, Xinyan, Lu, Chunxin, Hu, Siqi, Wang, Zhaoyang, Shi, Zhongfeng, Zhong, Wei, Xiao, Zhiyin, Liu, Xiaoming
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.01.2025
• Subjects: Aerobic oxidation of alcohols; Cu-Cu2O catalyst; Heterojunctions and band bending; MoS2; Synergistic effect; Aerobic oxidation of alcohols; Synergistic effect; Cu-Cu2O catalyst; MoS2; Heterojunctions and band bending
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.161144

Bulky MoS2 possesses larger work function than Cu2O and thus, lowers the VBM level of Cu2O in Cu-Cu2O/MoS2. However, the work functions of MoS2 flakes of limited layers lowers its work function, which raises the VBM level of Cu2O, and enhance the catalysis. The quantity of the flakes is small, but their impact on the electronic structure is significant. Therefore, despite that the bulky MoS2 would not be beneficial to the catalysis due to its larger work function, the MoS2-based composite material greatly improves the aerobic oxidation reaction owing to the presence of the flakes of thin layers of MoS2. [Display omitted] •Bulky MoS2 contains a certain MoS2 flakes of limited thickness after ball milling process.•Cu-Cu2O composite formation significantly enhances aerobic oxidation of benzylic alcohols due to the presence of the flakes.•The enhancement is attributed to the decrease in work function of MoS2 flakes as the thickness of the flakes decreases. Cuprous oxide (Cu2O), as a common transition metal semiconductor material, has found extensive applications and research in the field of catalysis due to its unique physicochemical properties. To improve its catalytic performance, introducing carriers to form composite materials with Cu2O has proven to be a promising strategy for enhancing its stability, activity, and selectivity. In this study, we introduced MoS2 to form a composite material with Cu-Cu2O, investigating the impact of MoS2 on the activity of Cu-Cu2O in selective alcohol oxidation. The results demonstrate a significant improvement in the catalytic activity of Cu-Cu2O upon the introduction of MoS2. Further investigations substantiate the close correlation between the enhanced activity of Cu-Cu2O and the interaction with thin layered MoS2 flakes. The quantity of the thin layered MoS2 is small but its impact on the catalytic activity is significant. It induces changes in the band and electronic structures of Cu-Cu2O, and the changes facilitate the activation of O2 and electron transfer in the oxidation, and thus promote the catalysis.