摘要
The gas-phase dehydrogenation of 1,6-hexanediol(1,6-HDO)toε-caprolactone(ε-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 Hüttig temperature(<150℃ vs.>250℃ of reaction temperature).Herein,we report a highly efficient silica-encapsulated nano-Cu catalyst(Cu@SiO_(2)/SiO_(2))prepared via a complexation–impregnation method for the dehydrogenation of 1,6-HDO,exhibiting a 1,6-HDO conversion of 95.3%andε-CL selectivity of 80.0%at 270℃.The catalyst also has the outstanding thermal stability(without sintering up to 270℃ for 100 h on stream),which can be attributed to the effective encapsulation of the SiO_(2)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 toε-CL.The synergistic effect of Cu+and Cu^(0) benefits the conversion ofε-CL to 2-methylcyclopentanone(2-MCPN).This study is beneficial for designing the high-performance Cu-based catalysts for 1,6-HDO toε-CL,understanding the reaction network of 1,6-HDO dehydrogenation over the Cu-based catalysts,and offering a strong foundation for the largescale production ofε-CL.
基金
the National Natural Science Foundation of China(Nos.22179038,22272053,22072043,21773069,and 21703069)
the Special Project for Peak Carbon Dioxide Emissions-Carbon Neutrality(No.21DZ1206700)from the Shanghai Municipal Science
Technology Commission,and the Key Basic Research Project(No.18JC1412100)from the Shanghai Municipal Science and Technology Commission.
