A carbon solid acid catalyst was prepared by the sulfonation of partially carbonized peanut shell with concentrated H2SO4. The structure and acidity of the catalyst were characterized by Fourier transform infrared spe...A carbon solid acid catalyst was prepared by the sulfonation of partially carbonized peanut shell with concentrated H2SO4. The structure and acidity of the catalyst were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, thermogravimetric analysis, X‐ray photoelectron spectroscopy, and elemental analysis, which showed that it was an amorphous carbon material composed of aromatic carbon sheets in random orientations. Sulfonic acid groups were present on the surface at a density of 0.81 mmol/g. The carbon solid acid catalyst showed better performance than HZSM‐5 for the esterification of cyclohexene with formic acid. At a3：1 molar ratio of formic acid to cyclohexene, catalyst loading of 0.07 g/mL of cyclohexene, and reaction time of 1 h at 413 K, the cyclohexene conversion was 88.4% with 97.3% selectivity to cyclohexyl formate. The carbon solid acid catalyst showed better reusability than HZSM‐5 because its large pores were minimally affected by the accumulation of oligomerized cyclohexene, which deactivated HZSM‐5. The activity of the carbon solid acid catalyst decreased somewhat in the first two recycles due to the leaching of polycyclic aromatic hydrocarbon containing –SO3H groups and then it remained constant in the following reuse.展开更多
To acquire the synergy effects between Sn and Cu for the jointly high Faradaic efficiency and current density,we develop a novel strategy to design the Sn-Cu alloy catalyst via a decorated co-electrodeposition method ...To acquire the synergy effects between Sn and Cu for the jointly high Faradaic efficiency and current density,we develop a novel strategy to design the Sn-Cu alloy catalyst via a decorated co-electrodeposition method for CO2 electroreduction to formate.The Sn-Cu alloy shows high formate Faradaic efficiency of 82.3%±2.1% and total C1 products Faradaic efficiency of 90.0%±2.7% at^-1.14 V vs.reversible hydrogen electrode(RHE).The current density and mass activity of formate reach as high as(79.0±0.4)mA cm^-2 and(1490.6±7.5)m A mg^-1 at^-1.14 V vs.RHE.Theoretical calculations suggest that Sn-Cu alloy can obtain high Faradaic efficiency for CO2 electroreduction by suppressing the competitive hydrogen evolution reaction and that the formate formation follows the path of CO2→HCOO*→HCOOH.The stepped(211)surface of Sn-Cu alloy is beneficial towards selective formate production.展开更多
It is important to screen strains that can decompose polycyclic aromatic hydrocarbons （PAHs） completely and rapidly with good adaptability for bioremedlation in a local area. A bacterial strain JM2, which uses pbena...It is important to screen strains that can decompose polycyclic aromatic hydrocarbons （PAHs） completely and rapidly with good adaptability for bioremedlation in a local area. A bacterial strain JM2, which uses pbenanthrene as its sole carbon source, was isolated from the active sewage sludge from a chemical plant in Jilin, China and identified as Pseudomonas based on 16S rDNA gene sequence analysis. Although the optimal growth conditions were determined to be pH 6.0 and 37~C, JM2 showed a broad pH and temperature profile. At pH 4.5 and 9.3, JM2 could degrade more than 40% of fluorene and phenanthrene （50 mg/L each） within 4 days. In addition, when the temperature was as low as 4~C, JM2 could degrade up to 24% fluorene and 12% phenanthrene. This showed the potential for JM2 to be applied in bioremediation over winter or in cold regions. Moreover, a nutrient augmentation study showed that adding formate into media could promote PAH degradation, while the supplement of salicylate had an inhibitive effect. Furthermore, in a metabolic pathway study, salicylate, phthalic acid, and 9-fluorenone were detected during the degradation of fluorene or phenanthrene. In conclusion, Pseudomonas sp. JM2 is a high performance strain in the degradation of fluorene and phenanthrene under extreme pH and temperature conditions. It might be useful in the bioremediation of PAHs.展开更多
基金supported by the National Natural Science Foundation of China(2123600121176056)+1 种基金the Programme for 100 Excellent Talents in Universities of Hebei Province(II)(BR2-208)the Natural Science Foundation of Hebei Province(B2015202228)~~
文摘A carbon solid acid catalyst was prepared by the sulfonation of partially carbonized peanut shell with concentrated H2SO4. The structure and acidity of the catalyst were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, thermogravimetric analysis, X‐ray photoelectron spectroscopy, and elemental analysis, which showed that it was an amorphous carbon material composed of aromatic carbon sheets in random orientations. Sulfonic acid groups were present on the surface at a density of 0.81 mmol/g. The carbon solid acid catalyst showed better performance than HZSM‐5 for the esterification of cyclohexene with formic acid. At a3：1 molar ratio of formic acid to cyclohexene, catalyst loading of 0.07 g/mL of cyclohexene, and reaction time of 1 h at 413 K, the cyclohexene conversion was 88.4% with 97.3% selectivity to cyclohexyl formate. The carbon solid acid catalyst showed better reusability than HZSM‐5 because its large pores were minimally affected by the accumulation of oligomerized cyclohexene, which deactivated HZSM‐5. The activity of the carbon solid acid catalyst decreased somewhat in the first two recycles due to the leaching of polycyclic aromatic hydrocarbon containing –SO3H groups and then it remained constant in the following reuse.
基金supported by the National Key R&D Program of China(2017YFA0700102)the National Natural Science Foundation of China(21573222,91545202,21802124,91945302 and 91845103)+6 种基金Dalian National Laboratory for Clean Energy(DNL180404)Dalian Institute of Chemical Physics(DICP DMTO201702)Dalian Outstanding Young Scientist Foundation(2017RJ03)Liaoning Revitalization Talents Program(XLYC1907099)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17020200)the financial support from CAS Youth Innovation Promotion(2015145)the financial support from the China Postdoctoral Science Foundation(2018M630307 and 2019T120220)。
文摘To acquire the synergy effects between Sn and Cu for the jointly high Faradaic efficiency and current density,we develop a novel strategy to design the Sn-Cu alloy catalyst via a decorated co-electrodeposition method for CO2 electroreduction to formate.The Sn-Cu alloy shows high formate Faradaic efficiency of 82.3%±2.1% and total C1 products Faradaic efficiency of 90.0%±2.7% at^-1.14 V vs.reversible hydrogen electrode(RHE).The current density and mass activity of formate reach as high as(79.0±0.4)mA cm^-2 and(1490.6±7.5)m A mg^-1 at^-1.14 V vs.RHE.Theoretical calculations suggest that Sn-Cu alloy can obtain high Faradaic efficiency for CO2 electroreduction by suppressing the competitive hydrogen evolution reaction and that the formate formation follows the path of CO2→HCOO*→HCOOH.The stepped(211)surface of Sn-Cu alloy is beneficial towards selective formate production.
基金supported by the National High Technology Research and Development Program (863) of China (No.2004AA649070)
文摘It is important to screen strains that can decompose polycyclic aromatic hydrocarbons （PAHs） completely and rapidly with good adaptability for bioremedlation in a local area. A bacterial strain JM2, which uses pbenanthrene as its sole carbon source, was isolated from the active sewage sludge from a chemical plant in Jilin, China and identified as Pseudomonas based on 16S rDNA gene sequence analysis. Although the optimal growth conditions were determined to be pH 6.0 and 37~C, JM2 showed a broad pH and temperature profile. At pH 4.5 and 9.3, JM2 could degrade more than 40% of fluorene and phenanthrene （50 mg/L each） within 4 days. In addition, when the temperature was as low as 4~C, JM2 could degrade up to 24% fluorene and 12% phenanthrene. This showed the potential for JM2 to be applied in bioremediation over winter or in cold regions. Moreover, a nutrient augmentation study showed that adding formate into media could promote PAH degradation, while the supplement of salicylate had an inhibitive effect. Furthermore, in a metabolic pathway study, salicylate, phthalic acid, and 9-fluorenone were detected during the degradation of fluorene or phenanthrene. In conclusion, Pseudomonas sp. JM2 is a high performance strain in the degradation of fluorene and phenanthrene under extreme pH and temperature conditions. It might be useful in the bioremediation of PAHs.
