评述了近3年来在石墨烯(graphene)制备化学、石墨烯化学改性、石墨烯表面化学和催化等方面取得的重要进展.阐述了通过化学方法实现非支撑(freestan ding)或准非支撑(quasifree-standing)石墨烯结构的可控和规模制备;通过表面反应对石墨...评述了近3年来在石墨烯(graphene)制备化学、石墨烯化学改性、石墨烯表面化学和催化等方面取得的重要进展.阐述了通过化学方法实现非支撑(freestan ding)或准非支撑(quasifree-standing)石墨烯结构的可控和规模制备;通过表面反应对石墨烯进行掺杂和官能化,制备了石墨烷、石墨烯氧化物等具有特殊结构和性质的石墨烯相关化合物;这些石墨烯及石墨烯相关材料(graphene and related materials)在催化、储氢等领域展现出非常重要的应用前景.展开更多
The catalytic performance of solid catalysts depends on the properties of the catalytically active sites and their accessibility to reactants, which are significantly affected by the microstructure（morphology, shape,...The catalytic performance of solid catalysts depends on the properties of the catalytically active sites and their accessibility to reactants, which are significantly affected by the microstructure（morphology, shape, size, texture, and surface structure） and surface chemistry（elemental components and chemical states）. The development of facile and efficient methods for tailoring the microstructure and surface chemistry is a hot topic in catalysis. This contribution reviews the state of the art in modulating the microstructure and surface chemistry of carbocatalysts by both bottom‐up and top‐down strategies and their use in the oxidative dehydrogenation（ODH） and direct dehydrogenation（DDH） of hydrocarbons including light alkanes and ethylbenzene to their corresponding olefins, important building blocks and chemicals like oxygenates. A concept of microstructure and surface chemistry tuning of the carbocatalyst for optimized catalytic performance and also for the fundamental understanding of the structure‐performance relationship is discussed. We also highlight the importance and challenges in modulating the microstructure and surface chemistry of carbocatalysts in ODH and DDH reactions of hydrocarbons for the highly‐efficient, energy‐saving,and clean production of their corresponding olefins.展开更多
It is reported for the first time that the Pt - Ru/C catalyst was prepared with the solid phase reaction method.Cyclic voltammetric measurements indicated that the anodic peak potential of ethanol at the electrode wit...It is reported for the first time that the Pt - Ru/C catalyst was prepared with the solid phase reaction method.Cyclic voltammetric measurements indicated that the anodic peak potential of ethanol at the electrode with the Pt - Ru/C catalyst prepared with the solid phase reaction method was0.54V and the peak current was100mA · cm -2 .While the anodic peak potential and peak current were0.64V and43mA · cm -2 respectively at the Pt - Ru/C catalyst prepared with the traditional liquid phase reaction method.It illustrated that the electrocatalytic activity of the Pt - Ru/C catalyst prepared with the solid phase reaction method was much better than that of the Pt - Ru/C catalyst prepared with the traditional liquid phase reaction method.It is because the Pt - Ru/C catalyst prepared with the solid phase reaction method is of low crystallinity and high dispersivity.展开更多
A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characteriza...A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characterization reveal that PtgFe alloy formation occurs during high-temperature reduction and that unstable Fe species are dissolved into acid solution. The difference in Fe concentration from the core region to the surface and strong O-Fe bonding may drive the outward diffusion of Fe to the highly corrugated Pt-skeleton, and the resulting highly dispersed surface FeOx is stable in acidic medium, leading to the construction of a PtBFe@Pt-FeOx architecture. The as prepared PtFe/C catalyst demonstrates a higher activity and comparable durability for the oxygen reduction reaction compared with a Pt/C catalyst, which might be due to the synergetic effect of surface and subsurface Fe species in the PtFe/C catalyst.展开更多
Developing efficient metal-free bi-functional electrocatalysts is required to reduce costs and improve the slow oxygen reduction reaction （ORR） and oxygen evo- lution reaction （OER） kinetics in electrochemical sys...Developing efficient metal-free bi-functional electrocatalysts is required to reduce costs and improve the slow oxygen reduction reaction （ORR） and oxygen evo- lution reaction （OER） kinetics in electrochemical systems. Porous N-doped carbon nanotubes （NCNTs） were fabri- cated by KOH activation and pyrolysis of polypyrrole nanotubes. The NCNTs possessed a large surface area of more than 1,000 m2 g-1. NCNT electrocatalysts, particu- larly those annealed at 900 ℃, exhibited excellent ORR electrocatalytic performance. Specifically, they yielded a more positive onset potential, higher current density, and long-term operation stability in alkaline media, when compared with a commercially available 20 wt% Pt/C catalyst. This resulted from the synergetic effect between the dominant pyridinic/graphitic-N species and the porous tube structures. The NCNT electrocatalyst also exhibited good performance for the OER. The metal-free porous nitrogen-doped carbon nanomaterials were prepared from low cost and environmentally friendly precursors. They are potential alternatives to Pt/C catalysts, for electrochemical energy conversion and storage.展开更多
文摘评述了近3年来在石墨烯(graphene)制备化学、石墨烯化学改性、石墨烯表面化学和催化等方面取得的重要进展.阐述了通过化学方法实现非支撑(freestan ding)或准非支撑(quasifree-standing)石墨烯结构的可控和规模制备;通过表面反应对石墨烯进行掺杂和官能化,制备了石墨烷、石墨烯氧化物等具有特殊结构和性质的石墨烯相关化合物;这些石墨烯及石墨烯相关材料(graphene and related materials)在催化、储氢等领域展现出非常重要的应用前景.
基金supported by the National Natural Science Foundation of China(21276041)the Program for New Century Excellent Talents in University of Ministry of Education of China(NCET-12-0079)+1 种基金the Natural Science Foundation of Liaoning Province(2015020200)the Fundamental Research Funds for the Central Universities(DUT15LK41)~~
文摘The catalytic performance of solid catalysts depends on the properties of the catalytically active sites and their accessibility to reactants, which are significantly affected by the microstructure（morphology, shape, size, texture, and surface structure） and surface chemistry（elemental components and chemical states）. The development of facile and efficient methods for tailoring the microstructure and surface chemistry is a hot topic in catalysis. This contribution reviews the state of the art in modulating the microstructure and surface chemistry of carbocatalysts by both bottom‐up and top‐down strategies and their use in the oxidative dehydrogenation（ODH） and direct dehydrogenation（DDH） of hydrocarbons including light alkanes and ethylbenzene to their corresponding olefins, important building blocks and chemicals like oxygenates. A concept of microstructure and surface chemistry tuning of the carbocatalyst for optimized catalytic performance and also for the fundamental understanding of the structure‐performance relationship is discussed. We also highlight the importance and challenges in modulating the microstructure and surface chemistry of carbocatalysts in ODH and DDH reactions of hydrocarbons for the highly‐efficient, energy‐saving,and clean production of their corresponding olefins.
文摘It is reported for the first time that the Pt - Ru/C catalyst was prepared with the solid phase reaction method.Cyclic voltammetric measurements indicated that the anodic peak potential of ethanol at the electrode with the Pt - Ru/C catalyst prepared with the solid phase reaction method was0.54V and the peak current was100mA · cm -2 .While the anodic peak potential and peak current were0.64V and43mA · cm -2 respectively at the Pt - Ru/C catalyst prepared with the traditional liquid phase reaction method.It illustrated that the electrocatalytic activity of the Pt - Ru/C catalyst prepared with the solid phase reaction method was much better than that of the Pt - Ru/C catalyst prepared with the traditional liquid phase reaction method.It is because the Pt - Ru/C catalyst prepared with the solid phase reaction method is of low crystallinity and high dispersivity.
基金This work was financially supported by the Ministry of Science and Technology of China （Grants 2012CB215500 and 2013CB933100） and the National Natural Science Foundation of China （Grants 21103178 and 21033009）.
文摘A PtFe/C catalyst has been synthesized by impregnation and high-temperature reduction followed by acid-leaching. X-ray diffraction, X-ray photoelectron spectroscopy and X-ray atomic near edge spectroscopy characterization reveal that PtgFe alloy formation occurs during high-temperature reduction and that unstable Fe species are dissolved into acid solution. The difference in Fe concentration from the core region to the surface and strong O-Fe bonding may drive the outward diffusion of Fe to the highly corrugated Pt-skeleton, and the resulting highly dispersed surface FeOx is stable in acidic medium, leading to the construction of a PtBFe@Pt-FeOx architecture. The as prepared PtFe/C catalyst demonstrates a higher activity and comparable durability for the oxygen reduction reaction compared with a Pt/C catalyst, which might be due to the synergetic effect of surface and subsurface Fe species in the PtFe/C catalyst.
基金This work was supported by the National Nat- ural Science Foundation of China （51273008, 51473008）, and the National Basic Research Program of China （2012CB933200）.
文摘Developing efficient metal-free bi-functional electrocatalysts is required to reduce costs and improve the slow oxygen reduction reaction （ORR） and oxygen evo- lution reaction （OER） kinetics in electrochemical systems. Porous N-doped carbon nanotubes （NCNTs） were fabri- cated by KOH activation and pyrolysis of polypyrrole nanotubes. The NCNTs possessed a large surface area of more than 1,000 m2 g-1. NCNT electrocatalysts, particu- larly those annealed at 900 ℃, exhibited excellent ORR electrocatalytic performance. Specifically, they yielded a more positive onset potential, higher current density, and long-term operation stability in alkaline media, when compared with a commercially available 20 wt% Pt/C catalyst. This resulted from the synergetic effect between the dominant pyridinic/graphitic-N species and the porous tube structures. The NCNT electrocatalyst also exhibited good performance for the OER. The metal-free porous nitrogen-doped carbon nanomaterials were prepared from low cost and environmentally friendly precursors. They are potential alternatives to Pt/C catalysts, for electrochemical energy conversion and storage.
