Aligned carbon nanotubes(CNTs)were synthesized by nebulized spray pyrolysis of solutions of organometallics in carbon precursor solvents.Four types of straight-chained alkanes including n-pentane,n-hexane,n-heptane an...Aligned carbon nanotubes(CNTs)were synthesized by nebulized spray pyrolysis of solutions of organometallics in carbon precursor solvents.Four types of straight-chained alkanes including n-pentane,n-hexane,n-heptane and n-octane were used as precursor solvents for synthesis of aligned CNTs.The results from scanning electron microscopy,transmission electron microscopy and Raman spectroscopy show that the CNTs obtained from them have different diameters and degrees of graphitization. It is found that the n-heptane is the most suitable for the growth of aligned CNTs with high quality and yield.The thermodynamic properties of precursory carbon sources such as boiling point and formation enthalpy are considered to play a decisive role in the synthesis of CNTs.It will be very helpful for the controllable preparation of aligned CNTs at relatively low cost.展开更多
Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point waxes.Unlike conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and p...Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point waxes.Unlike conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and polyethylene cracking)typically resulting in wide n-alkane distributions,the elaborate design strategy presented herein allows the direct synthesis of pure,long n-alkanes using a modular splicing method with acetone,furfural,and fatty acid anhydrides or acyl chlorides as bio-blocks.The herein approach is based on a simple four-step catalytic reaction scheme involving C–C chain elongation and C–O bond activation.The synthesized pure n-alkanes had a carbon chain length as high as C_(49)(total yield of 49%).The synthesis approach also allows to selectively prepare n-alkanes with even and odd carbon numbers ranging from C15 to C_(49).This process represents a great breakthrough in the synthesis of long-chain pure n-alkanes,surpassing the carbon number limitations reported in previous methodologies.展开更多
Methoxycarbonylation was performed on 1-heptene, 1-octene and 1-dodecene with Co(acac)(2) catalyst in the presence of UV light under ambient conditions.
基金Projects(50772033, 50972043) supported by the National Natural Science Foundation of ChinaProject(2007FJ3003) supported by the Natural Science Foundation of Hunan Province, China
文摘Aligned carbon nanotubes(CNTs)were synthesized by nebulized spray pyrolysis of solutions of organometallics in carbon precursor solvents.Four types of straight-chained alkanes including n-pentane,n-hexane,n-heptane and n-octane were used as precursor solvents for synthesis of aligned CNTs.The results from scanning electron microscopy,transmission electron microscopy and Raman spectroscopy show that the CNTs obtained from them have different diameters and degrees of graphitization. It is found that the n-heptane is the most suitable for the growth of aligned CNTs with high quality and yield.The thermodynamic properties of precursory carbon sources such as boiling point and formation enthalpy are considered to play a decisive role in the synthesis of CNTs.It will be very helpful for the controllable preparation of aligned CNTs at relatively low cost.
基金supported by National Natural Science Foundation of China(General Program,No.22372060)Shanghai Municipal Science and Technology Commission Project(No.22dz1209300)National Natural Science Youth Fund(No.22205065)。
文摘Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point waxes.Unlike conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and polyethylene cracking)typically resulting in wide n-alkane distributions,the elaborate design strategy presented herein allows the direct synthesis of pure,long n-alkanes using a modular splicing method with acetone,furfural,and fatty acid anhydrides or acyl chlorides as bio-blocks.The herein approach is based on a simple four-step catalytic reaction scheme involving C–C chain elongation and C–O bond activation.The synthesized pure n-alkanes had a carbon chain length as high as C_(49)(total yield of 49%).The synthesis approach also allows to selectively prepare n-alkanes with even and odd carbon numbers ranging from C15 to C_(49).This process represents a great breakthrough in the synthesis of long-chain pure n-alkanes,surpassing the carbon number limitations reported in previous methodologies.
文摘Methoxycarbonylation was performed on 1-heptene, 1-octene and 1-dodecene with Co(acac)(2) catalyst in the presence of UV light under ambient conditions.
