Catalytic performance of phosphate-modified carbon nanotube（PoCNT） catalysts for oxidative dehydrogenation（ODH） of n-butane has been systematically investigated. The Po CNT catalysts are characterized by SEM, TEM,...Catalytic performance of phosphate-modified carbon nanotube（PoCNT） catalysts for oxidative dehydrogenation（ODH） of n-butane has been systematically investigated. The Po CNT catalysts are characterized by SEM, TEM, XPS and TG techniques. We set the products selectivity as a function of butane conversion over various phosphate loading, and it is found that the PoCNT catalyst with the 0.8% phosphate weight loading（0.8PoCNT） exhibits the best catalytic performance. When the phosphate loading is higher than 0.8 wt%, the difference of catalytic activity among the PoCNT catalysts is neglectable. Consequently, the ODH of n-butane over the 0.8PoCNT catalyst is particularly discussed via changing the reaction conditions including reaction temperatures, residence time and n-butane/O;ratios. The interacting mechanism of phosphate with the oxygen functional groups on the CNT surface is also proposed.展开更多
Carbon nanotubes (CNT) were modified bynitric acid oxidation. Infrared spectroscopy (IR) demon-strated that hydroxyl (—OH) and carbonyl (—C== O) func-tional groups were introduced to the surface of modifiedCNT. Micr...Carbon nanotubes (CNT) were modified bynitric acid oxidation. Infrared spectroscopy (IR) demon-strated that hydroxyl (—OH) and carbonyl (—C== O) func-tional groups were introduced to the surface of modifiedCNT. Micrometrics ASAP 2000 measurement showed that the surface area of modified CNT was slightly increased.Furthermore, the Pb2+ adsorption behavior on the surface of modified CNT has been investigated. The results indicate that the modified CNT has an exceptional adsorption capa-bility for Pb2+ removal. The adsorption isotherms are well described by the Langmuir equation under test temperatures and the kinetics level is three.展开更多
本文通过调节烧结温度设计构筑了一种纳米多面体颗粒堆积的中空球状Li Ni0.5Mn1.5O4材料,并进一步通过碳纳米管(CNT)的改性来提高材料的循环性能和高倍率性能.纳米中空结构不仅减少了锂离子的扩散路径,也保证了电解液和正极材料的充分接...本文通过调节烧结温度设计构筑了一种纳米多面体颗粒堆积的中空球状Li Ni0.5Mn1.5O4材料,并进一步通过碳纳米管(CNT)的改性来提高材料的循环性能和高倍率性能.纳米中空结构不仅减少了锂离子的扩散路径,也保证了电解液和正极材料的充分接触,三维网状CNT的改性提高了材料的电子导电率,从而明显改善了材料的循环和高倍率性能.最终得到的LNMO-850/CNT材料在5 C的电流密度下初始容量为127 m A h g-1,500次循环后容量保持在104 m A h g-1.而在20 C的高电流密度下容量仍达到121 m A h g-1,体现了材料优异的循环和高倍率性能.展开更多
基金supported by the National Natural Science Foundation of China(No.91545110,21573254,21203214,21133010,21473223,21261160487,51221264)the Institute of Metal Research,Youth Innovation Promotion Association(CAS)the Sinopec China and the Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDA09030103
文摘Catalytic performance of phosphate-modified carbon nanotube（PoCNT） catalysts for oxidative dehydrogenation（ODH） of n-butane has been systematically investigated. The Po CNT catalysts are characterized by SEM, TEM, XPS and TG techniques. We set the products selectivity as a function of butane conversion over various phosphate loading, and it is found that the PoCNT catalyst with the 0.8% phosphate weight loading（0.8PoCNT） exhibits the best catalytic performance. When the phosphate loading is higher than 0.8 wt%, the difference of catalytic activity among the PoCNT catalysts is neglectable. Consequently, the ODH of n-butane over the 0.8PoCNT catalyst is particularly discussed via changing the reaction conditions including reaction temperatures, residence time and n-butane/O;ratios. The interacting mechanism of phosphate with the oxygen functional groups on the CNT surface is also proposed.
基金the National Natural Science Foundation of China (Grant No.50178067)
文摘Carbon nanotubes (CNT) were modified bynitric acid oxidation. Infrared spectroscopy (IR) demon-strated that hydroxyl (—OH) and carbonyl (—C== O) func-tional groups were introduced to the surface of modifiedCNT. Micrometrics ASAP 2000 measurement showed that the surface area of modified CNT was slightly increased.Furthermore, the Pb2+ adsorption behavior on the surface of modified CNT has been investigated. The results indicate that the modified CNT has an exceptional adsorption capa-bility for Pb2+ removal. The adsorption isotherms are well described by the Langmuir equation under test temperatures and the kinetics level is three.
基金supported by the National Basic Research Program of China(2013CB934103 and 2012CB933003)the International Science&Technology Cooperation Program of China(2013DFA50840)+4 种基金the National Natural Science Foundation of China(51521001 and 51272197)the National Natural Science Fund for Distinguished Young Scholars(51425204)Hubei Province Natural Science Fund for Distinguished Young Scholars(2014CFA035)the Fundamental Research Funds for the Central Universities(WUT:2015-III-0322015-III-021)
文摘本文通过调节烧结温度设计构筑了一种纳米多面体颗粒堆积的中空球状Li Ni0.5Mn1.5O4材料,并进一步通过碳纳米管(CNT)的改性来提高材料的循环性能和高倍率性能.纳米中空结构不仅减少了锂离子的扩散路径,也保证了电解液和正极材料的充分接触,三维网状CNT的改性提高了材料的电子导电率,从而明显改善了材料的循环和高倍率性能.最终得到的LNMO-850/CNT材料在5 C的电流密度下初始容量为127 m A h g-1,500次循环后容量保持在104 m A h g-1.而在20 C的高电流密度下容量仍达到121 m A h g-1,体现了材料优异的循环和高倍率性能.
