In recent decade, Au nanoclusters of atomic precision （AunLm, where L= organic ligand： thiolate andphosphine） have been shown as a new promising nanogold catalyst. The well-defined AunLm catalystspossess unique ele...In recent decade, Au nanoclusters of atomic precision （AunLm, where L= organic ligand： thiolate andphosphine） have been shown as a new promising nanogold catalyst. The well-defined AunLm catalystspossess unique electronic properties and frameworks, providing an excellent opportunity to correlate theintrinsic catalytic behavior with the cluster＇s framework as well as to study the catalytic mechanismsover gold nanoclusters. In this review, we only demonstrate the important roles of the gold nanoclustersin the oxygen activation （e.g., 302 to 102） and their selective oxidations in the presence of oxygen （e.g., COto C02, sulfides to sulfoxides, alcohol to aldehyde, styrene to styrene epoxide, amines to imines, andglucose to gluconic acid）. The size-specificity （Au25 （1.3 nm）, Au38 （].5 nm）, Au144 （1.9 nm）, etc.）, ligandengineering （e.g., aromatic vs aliphatic）, and doping effects （e.g., copper, silver, palladium, and platinum）are discussed in details. Finally, the proposed reactions＇ mechanism and the relationships of clusters＇structure and activity at the atomic level also are presented.展开更多
Titania（TiO2） nanorod powder was prepared by nonhydrolytic sol-gel method using titanic chloride（TiCl4） as titanium source, methylene dichloride（CH2Cl2） as solvent, absolute ethyl alcohol（CH（-3）CH2OH） as oxy...Titania（TiO2） nanorod powder was prepared by nonhydrolytic sol-gel method using titanic chloride（TiCl4） as titanium source, methylene dichloride（CH2Cl2） as solvent, absolute ethyl alcohol（CH（-3）CH2OH） as oxygen donor. The effects of Si^（4＋） doping on the TiO2 nanocrystalline phase transformation temperature were systematically researched. The results showed that when the molar ratio of Ti^（4＋） to Si^（4＋） is 1 to1.3, TiO2 prepared by calcination at 1 100 ℃ for 1 hour exhibits rod shape and has good photocatalytic activity. Doping of Si^（4＋） makes glass phase core-shell structure forming on the surface of anatase crystal particles, which can inhibit crystal phase transformation and raise the transformation temperature, making TiO2 stable in anatase phase at 1 200 ℃.展开更多
Structure characteristics about activated carbon fibers (ACF) and polyimide (P84) doped ACF modified by HNO3 solution were studied to apply in mercury removal in coal-fired flue gases. The P84, which was always used i...Structure characteristics about activated carbon fibers (ACF) and polyimide (P84) doped ACF modified by HNO3 solution were studied to apply in mercury removal in coal-fired flue gases. The P84, which was always used in the non-woven fabric for bag filter, was intermingled with polyacrylonitrile-based ACF (PAN-ACF) in the weight ratio of 1∶1 in order to make the doped ACF with P84 (doped-ACF-P84). Then the doped-ACF-P84 fibers were modified by HNO3 solution. The structure and morphology of doped-ACF-P84 were characterized and compared with those of ACF and doped-ACF-P84 modified by HNO3solution. The results show that the modified doped-ACF-P84 fibers have almost the same pore structure and specific surface area comparing with the original one. However, contrasted with the original PAN-ACF, the doped-ACF-P84 fibers modified by HNO3 solution have more oxygen-containing groups used for mercury removal. In particular, they have more lactone and carboxyl groups.展开更多
This paper investigates Mn-doped LiCoPO4 material using first-principles calculations. Results indicate that the volume change of LiMnxCo1-xPO4 to MnxCo1-xPO4 is smaller than that of undoped LiCoPO4, which is responsi...This paper investigates Mn-doped LiCoPO4 material using first-principles calculations. Results indicate that the volume change of LiMnxCo1-xPO4 to MnxCo1-xPO4 is smaller than that of undoped LiCoPO4, which is responsible for the excellent tolerance of repeated cycling in lithium ion batteries. Combining first-principles calculations with basic thermodynamics, we calculate the average intercalation voltage of Mn-doped LiCoPO4. It is shown that the redox couple Mn3＋/Mn2＋ can be observed with increasing Mn content. Therefore, the Mn ion displays some electrochemical activity during discharge/charge of LiMnxCo1-xPO4 due to the coexistence of Co and Mn.展开更多
Subject Code:B01With the support by the National Natural Science Foundation of China,a creative study by the research group led by Prof.Chen Qianwang(陈乾旺)from the University of Science and Technology of China and H...Subject Code:B01With the support by the National Natural Science Foundation of China,a creative study by the research group led by Prof.Chen Qianwang(陈乾旺)from the University of Science and Technology of China and High Magnetic Field Laboratory,Hefei Institutes of Physical Science,Chinese Academy of展开更多
基金financial support by the Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi(OIT)Shanxi Province Hundred Talent Project
文摘In recent decade, Au nanoclusters of atomic precision （AunLm, where L= organic ligand： thiolate andphosphine） have been shown as a new promising nanogold catalyst. The well-defined AunLm catalystspossess unique electronic properties and frameworks, providing an excellent opportunity to correlate theintrinsic catalytic behavior with the cluster＇s framework as well as to study the catalytic mechanismsover gold nanoclusters. In this review, we only demonstrate the important roles of the gold nanoclustersin the oxygen activation （e.g., 302 to 102） and their selective oxidations in the presence of oxygen （e.g., COto C02, sulfides to sulfoxides, alcohol to aldehyde, styrene to styrene epoxide, amines to imines, andglucose to gluconic acid）. The size-specificity （Au25 （1.3 nm）, Au38 （].5 nm）, Au144 （1.9 nm）, etc.）, ligandengineering （e.g., aromatic vs aliphatic）, and doping effects （e.g., copper, silver, palladium, and platinum）are discussed in details. Finally, the proposed reactions＇ mechanism and the relationships of clusters＇structure and activity at the atomic level also are presented.
基金Funded by the National Natural Science Foundation of China(No.51302064)
文摘Titania（TiO2） nanorod powder was prepared by nonhydrolytic sol-gel method using titanic chloride（TiCl4） as titanium source, methylene dichloride（CH2Cl2） as solvent, absolute ethyl alcohol（CH（-3）CH2OH） as oxygen donor. The effects of Si^（4＋） doping on the TiO2 nanocrystalline phase transformation temperature were systematically researched. The results showed that when the molar ratio of Ti^（4＋） to Si^（4＋） is 1 to1.3, TiO2 prepared by calcination at 1 100 ℃ for 1 hour exhibits rod shape and has good photocatalytic activity. Doping of Si^（4＋） makes glass phase core-shell structure forming on the surface of anatase crystal particles, which can inhibit crystal phase transformation and raise the transformation temperature, making TiO2 stable in anatase phase at 1 200 ℃.
基金National High Technology Research and Development Program,China(No.2008AA05Z305)
文摘Structure characteristics about activated carbon fibers (ACF) and polyimide (P84) doped ACF modified by HNO3 solution were studied to apply in mercury removal in coal-fired flue gases. The P84, which was always used in the non-woven fabric for bag filter, was intermingled with polyacrylonitrile-based ACF (PAN-ACF) in the weight ratio of 1∶1 in order to make the doped ACF with P84 (doped-ACF-P84). Then the doped-ACF-P84 fibers were modified by HNO3 solution. The structure and morphology of doped-ACF-P84 were characterized and compared with those of ACF and doped-ACF-P84 modified by HNO3solution. The results show that the modified doped-ACF-P84 fibers have almost the same pore structure and specific surface area comparing with the original one. However, contrasted with the original PAN-ACF, the doped-ACF-P84 fibers modified by HNO3 solution have more oxygen-containing groups used for mercury removal. In particular, they have more lactone and carboxyl groups.
基金Project supported by the National Natural Science Foundation of China(Grant No.50772039)the Science and Technology Bureau of Guangdong Province,China(Grant No.07118058)
文摘This paper investigates Mn-doped LiCoPO4 material using first-principles calculations. Results indicate that the volume change of LiMnxCo1-xPO4 to MnxCo1-xPO4 is smaller than that of undoped LiCoPO4, which is responsible for the excellent tolerance of repeated cycling in lithium ion batteries. Combining first-principles calculations with basic thermodynamics, we calculate the average intercalation voltage of Mn-doped LiCoPO4. It is shown that the redox couple Mn3＋/Mn2＋ can be observed with increasing Mn content. Therefore, the Mn ion displays some electrochemical activity during discharge/charge of LiMnxCo1-xPO4 due to the coexistence of Co and Mn.
文摘Subject Code:B01With the support by the National Natural Science Foundation of China,a creative study by the research group led by Prof.Chen Qianwang(陈乾旺)from the University of Science and Technology of China and High Magnetic Field Laboratory,Hefei Institutes of Physical Science,Chinese Academy of
