Core-shell Cu@SiO2/SiO2 catalyst for 1,6-hexanediol dehydrogenation to ε-caprolactone: High activity and stability from core-shell nanostructure

作者：Jiang, Fengyang; Lan, Tian; Sun, Jiaqiang^*; Zhao, Guofeng^*; Lu, Yong^*

来源：Nano Research, 2023, 16(10): 12270-12280.

DOI：10.1007/s12274-023-5891-8

• core-shell nanostructure
• Cu-based catalyst
• 1,6-hexanediol
• dehydrogenation
• epsilon-caprolactone

The gas-phase dehydrogenation of 1,6-hexanediol (1,6-HDO) to e-caprolactone (epsilon-CL) over the high-performance Cu-based catalysts is highly desirable, but with grand challenges, because the Cu nanoparticles (NPs) are easy to be sintered with the low Huttig temperature (< 150 degrees C vs. > 250 degrees C of reaction temperature). Herein, we report a highly efficient silica-encapsulated nano-Cu catalyst (Cu@SiO2/SiO2) prepared via a complexation-impregnation method for the dehydrogenation of 1,6-HDO, exhibiting a 1,6-HDO conversion of 95.3% and epsilon-CL selectivity of 80.0% at 270 degrees C. The catalyst also has the outstanding thermal stability (without sintering up to 270 degrees C for 100 h on stream), which can be attributed to the effective encapsulation of the SiO2 shell. In addition, the reaction network of 1,6-HDO dehydrogenation is proved. Finally, the pyridine-diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and in-situ X-ray photoelectron spectroscopy (XPS) reveal that the Cu-0 species favor the conversion of 1,6-HDO to epsilon-CL. The synergistic effect of Cu+ and Cu-0 benefits the conversion of epsilon-CL to 2-methylcyclopentanone (2-MCPN). This study is beneficial for designing the high-performance Cu-based catalysts for 1,6-HDO to epsilon-CL, understanding the reaction network of 1,6-HDO dehydrogenation over the Cu-based catalysts, and offering a strong foundation for the large-scale production of epsilon-CL.

• 单位
  中国科学院; y