2,5-dimethyfuran(DMF), which is produced from 5-hydroxymethyfurfural(HMF) by hydrodeoxygenation(HDO), is a high quality fuel due to the high heating value, the high octane number and the suitable boiling point. Select...2,5-dimethyfuran(DMF), which is produced from 5-hydroxymethyfurfural(HMF) by hydrodeoxygenation(HDO), is a high quality fuel due to the high heating value, the high octane number and the suitable boiling point. Selective hydrogenation of HMF into liquid fuel DMF has been widely researched. In this paper, Co_3O_4 catalyst was prepared by co-precipitation and was reduced at different temperatures to form Co–CoO_x catalysts. The characterization of catalysts was tested by XRD, TEM, XPS, TPR, BET and NH3-TPD.Co–CoO_x possessed a high amount of Co metal and CoO_x acidic sites, wherein Co worked as the active hydrogenation sites and CoO_x acted as the acid promoter to facilitate the selective HDO of HMF to DMF.The synergistic effect of Co–CoO_x is the key for HDO of HMF, obtaining 83.3% of DMF yield at 170 °C, 12 h and the reduction temperature of 400 °C. This method not only saves the catalyst cost, but also promotes the utilization of biomass energy.展开更多
New supported Raney-Cu catalyst was prepared from pseudo-boehmite powder and copper aluminum alloy powder. It could be used in a continuous-flow fixed-bed reactor and it was also a good catalyst for hydrogenolysis of ...New supported Raney-Cu catalyst was prepared from pseudo-boehmite powder and copper aluminum alloy powder. It could be used in a continuous-flow fixed-bed reactor and it was also a good catalyst for hydrogenolysis of glycerol to propylene glycol after the two raw materials were processed by the following procedures: molding, drying, calcination, and leaching. XRD, H2-TPR, as well as SEM technique were employed to study the physicochemical properties of the catalysts, and the hydrogenolysis of glycerol to 1,2-propylene glycol (1,2-PDO) was used as a probe to evaluate the performance of supported skeletal copper catalysts. The test result indicated that CuAl2 was the main crystal phase of precursor after the dried strips were calcined at 850 °C in air. A part of CuAl2 was oxidized to α-Al2O3, which was the main contributor to the strength of Raney-Cu/Al2O3, while the remaining CuAl2 was converted to active skeletal copper after the leaching process. The effects of reaction temperature, hydrogen pressure, LHSV, hydrogen-oil ratio, glycerol concentration, and alkaline additives on the catalytic performance were studied in water or ethanol, respectively. Conversion of glycerol and selectivity of 1,2-PDO were 30.9% and 91.4% in water, or 99.0% and 73.6% in the ethanol system, respectively, when the reaction was performed at a temperature of 215 °C, a H2 pressure of 3 MPa, a LHSV of 1.0 h-1, a hydrogen-oil ratio of 500, and a glycerol concentration of 20%(ethyl alcohol solution).展开更多
基金financially supported by the National Natural Science Foundation of China(51576199 and 51536009)the Natural Science Fund of Guangdong Province(2017A030308010)
文摘2,5-dimethyfuran(DMF), which is produced from 5-hydroxymethyfurfural(HMF) by hydrodeoxygenation(HDO), is a high quality fuel due to the high heating value, the high octane number and the suitable boiling point. Selective hydrogenation of HMF into liquid fuel DMF has been widely researched. In this paper, Co_3O_4 catalyst was prepared by co-precipitation and was reduced at different temperatures to form Co–CoO_x catalysts. The characterization of catalysts was tested by XRD, TEM, XPS, TPR, BET and NH3-TPD.Co–CoO_x possessed a high amount of Co metal and CoO_x acidic sites, wherein Co worked as the active hydrogenation sites and CoO_x acted as the acid promoter to facilitate the selective HDO of HMF to DMF.The synergistic effect of Co–CoO_x is the key for HDO of HMF, obtaining 83.3% of DMF yield at 170 °C, 12 h and the reduction temperature of 400 °C. This method not only saves the catalyst cost, but also promotes the utilization of biomass energy.
基金financially supported by the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions(CIT&TCD20130325)the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality (IDHT20180508)
文摘New supported Raney-Cu catalyst was prepared from pseudo-boehmite powder and copper aluminum alloy powder. It could be used in a continuous-flow fixed-bed reactor and it was also a good catalyst for hydrogenolysis of glycerol to propylene glycol after the two raw materials were processed by the following procedures: molding, drying, calcination, and leaching. XRD, H2-TPR, as well as SEM technique were employed to study the physicochemical properties of the catalysts, and the hydrogenolysis of glycerol to 1,2-propylene glycol (1,2-PDO) was used as a probe to evaluate the performance of supported skeletal copper catalysts. The test result indicated that CuAl2 was the main crystal phase of precursor after the dried strips were calcined at 850 °C in air. A part of CuAl2 was oxidized to α-Al2O3, which was the main contributor to the strength of Raney-Cu/Al2O3, while the remaining CuAl2 was converted to active skeletal copper after the leaching process. The effects of reaction temperature, hydrogen pressure, LHSV, hydrogen-oil ratio, glycerol concentration, and alkaline additives on the catalytic performance were studied in water or ethanol, respectively. Conversion of glycerol and selectivity of 1,2-PDO were 30.9% and 91.4% in water, or 99.0% and 73.6% in the ethanol system, respectively, when the reaction was performed at a temperature of 215 °C, a H2 pressure of 3 MPa, a LHSV of 1.0 h-1, a hydrogen-oil ratio of 500, and a glycerol concentration of 20%(ethyl alcohol solution).
