摘要
The tandem hydrolysis and hydrogenation of saccharides into sorbitol is an especially attractive reaction in the conversion of biomass. Here, an economical and efficient bimetallic catalyst for the transformation of glucose and cellobiose into sorbitol is reported. Non-precious metal based catalysts such as NiCo, Ni, and Co, were prepared via modified impregnation method, and NiCo/HZSM-5 showed superior performance for the synthesis of sorbitol(86.9% from cellobiose, 98.6% from D-glucose).Various characterizations, such as Brunner-Emmet-Teler(BET), X-ray diffraction(XRD), transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS), confirmed that NiCo alloy formed and highly dispersed in NiCo/HZSM-5 catalyst. The high performance of fabricated catalyst would be attributed to the formation of nickel-cobalt alloy over HZSM-5 zeolite surface. High temperature and H_2 pressure were favorable for the tandem hydrolysis and hydrogenation reaction. Besides,the reaction pathway was also proposed based on the kinetics study. Cellobitol was detected as the intermediate in the reaction mixture. Furthermore, in the catalytic stability study, it was found that active metal species of NiCo/HZSM-5 were stable. The deactivation of catalyst would be due to the covering of acidic sites over NiCo/HZSM-5.
The tandem hydrolysis and hydrogenation of saccharides into sorbitol is an especially attractive reaction in the conversion of biomass. Here, an economical and efficient bimetallic catalyst for the transformation of glucose and cellobiose into sorbitol is reported. Non-precious metal based catalysts such as NiCo, Ni, and Co, were prepared via modified impregnation method, and NiCo/HZSM-5 showed superior performance for the synthesis of sorbitol（86.9% from cellobiose, 98.6% from D-glucose）.Various characterizations, such as Brunner-Emmet-Teler（BET）, X-ray diffraction（XRD）, transmission electron microscopy（TEM） and X-ray photoelectron spectroscopy（XPS）, confirmed that NiCo alloy formed and highly dispersed in NiCo/HZSM-5 catalyst. The high performance of fabricated catalyst would be attributed to the formation of nickel-cobalt alloy over HZSM-5 zeolite surface. High temperature and H2 pressure were favorable for the tandem hydrolysis and hydrogenation reaction. Besides,the reaction pathway was also proposed based on the kinetics study. Cellobitol was detected as the intermediate in the reaction mixture. Furthermore, in the catalytic stability study, it was found that active metal species of NiCo/HZSM-5 were stable. The deactivation of catalyst would be due to the covering of acidic sites over NiCo/HZSM-5.
基金
supported by the National Natural Science Foundation of China (21732006, 21572212)
the Strategic Priority Research Program of the CAS (XDB20000000, XDA21060101)
Ministry of Science and Technology of China (2017YFA0303502)
the Fundamental Research Funds for the Central Universities (WK3530000001)
the Major Program of Development Foundation of Hefei Center for Physical Science and Technology (2017FXZY001)
