Increasingly stringent regulations in many countries require effective reduction and control of NOx emissions. To meet these limits, various methods have been exploited, among which the selective catalytic reduction o...Increasingly stringent regulations in many countries require effective reduction and control of NOx emissions. To meet these limits, various methods have been exploited, among which the selective catalytic reduction of NOx using ammonia as the reduc- rant （NH3-SCR） is the most favored technology. High catalytic activity, N2 selectivity and resistance to deactivation by sulfur, alkaline metals and hydrothermal conditions are the optimal properties of a successful SCR catalyst. Rare earth oxides, particularly CeO2, have been increasingly used to improve the catalytic activity and resistance to deactivation of deNOx catalysts, both modifying tradi- tional vanadium catalysts, and also developing novel catalysts, especially for low temperature applications. This review summarized the open literature concerning recent research and development progresses in the application of rare earths for NH3-SCR of NOx. Additionally, the roles of rare earths in enhancing the performance of NH3-SCR catalyst were reviewed.展开更多
Six new transition metal complexes, [Zn（HBTC）（PYTPY）]n·n PYTPY（1）, [Cu（HBTC）（PYTPY）]n·n PYTPY（2）, [Co（HBTC）（PYTPY）]n·n DMF（3）, [Mn（HBTC）（PYTPY）]n·n DMF（4）, [Cd（HBTC）（PYTP...Six new transition metal complexes, [Zn（HBTC）（PYTPY）]n·n PYTPY（1）, [Cu（HBTC）（PYTPY）]n·n PYTPY（2）, [Co（HBTC）（PYTPY）]n·n DMF（3）, [Mn（HBTC）（PYTPY）]n·n DMF（4）, [Cd（HBTC）（PYTPY）（H2O）]n·2nH2O（5）, and [Co（HBTC）（PYTPY）（H2O）2]（6）,（H3BTC = 1,3,5-benzenetricarboxylic acid, PYTPY = 4＇-（4-pyridyl）-2,2＇：6＇,2＇＇-terpyridine, DMF = N,N？-dimethylformamide）, have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. Complexes 1~5 all feature one-dimensional chain structures, and complex 6 exhibits a zero-dimensional structure. Complexes 1~5 present three-dimensional（3D） supramolecular frameworks via π-π stacking interactions, whenas 6 has also a 3D supramolecular structure assembled by hydrogen bonding. Meanwhile, complexes 1 ~ 6 exhibit the thermal stabilities and photoluminescent properties.展开更多
Cobalt and nickel complexes （la-ld and 2a-2d, respectively） supported by 2-imidate-pyridine ligands were synthesized and used for 1,3-butadiene polymerization. The complexes were characterized by IR and element anal...Cobalt and nickel complexes （la-ld and 2a-2d, respectively） supported by 2-imidate-pyridine ligands were synthesized and used for 1,3-butadiene polymerization. The complexes were characterized by IR and element analysis, and complex la was further characterized by single-crystal X-ray diffraction. The solid state structure of complex la displayed a distorted tetrahedral geometry. Upon activation with ethylaluminum sesquichloride （EASC）, all the complexes showed high activities toward 1,3-butadiene polymerization. The cobalt complexes produced polymers with high cis-1,4 contents and high molecular weights, while the nickel complexes displayed low cis-l,4 selectivity and the resulting polymers had low molecular weights. The catalytic activities of the complexes highly depended on the ligand structure. With the increment of polymerization temperature, the cis-1,4 content and the molecular weight of the resulting polymer decreased.展开更多
The development of efficient and stable non-noble metal-based electrocatalysts for the oxygen evolution reaction （OER） is one of the essential challenges for the upcoming hydrogen economy. Herein, three-dimensional ...The development of efficient and stable non-noble metal-based electrocatalysts for the oxygen evolution reaction （OER） is one of the essential challenges for the upcoming hydrogen economy. Herein, three-dimensional （3D） mesoporous nickel iron selenide with rose-like microsphere architecture was directly grown on Ni foam via a successive two-step hydrotherrnal method. The unique 3D mesoporous rose-like morphology leads to a higher number of active sites as well as fast mass and electron transport through the entire electrode, and facilitates the release of 02 bubbles formed during the OER catalysis. As a result, the synthesized Ni0.76Fe0.24Se exhibits superior OER performances, with an ultralow overpotential of 197 mV needed to produce a current density of 10 mA.cm-2 in 1 M KOH, outperforming all transition metal selenide OER catalysts reported to date.展开更多
基金supported by National Natural Science Foundation of China(51202126)Postdoctoral Science Foundation of China(2012M520266)Strategic Emerging Industry Development Funds of Shenzhen(JCYJ20120619152738634)
文摘Increasingly stringent regulations in many countries require effective reduction and control of NOx emissions. To meet these limits, various methods have been exploited, among which the selective catalytic reduction of NOx using ammonia as the reduc- rant （NH3-SCR） is the most favored technology. High catalytic activity, N2 selectivity and resistance to deactivation by sulfur, alkaline metals and hydrothermal conditions are the optimal properties of a successful SCR catalyst. Rare earth oxides, particularly CeO2, have been increasingly used to improve the catalytic activity and resistance to deactivation of deNOx catalysts, both modifying tradi- tional vanadium catalysts, and also developing novel catalysts, especially for low temperature applications. This review summarized the open literature concerning recent research and development progresses in the application of rare earths for NH3-SCR of NOx. Additionally, the roles of rare earths in enhancing the performance of NH3-SCR catalyst were reviewed.
基金Supported by the National Natural Science Foundation of China(No.21576112)Natural Science Foundation of Jilin Province(20150623024TC-19,20170520147JH)the Science and Technology Development Plan of Siping City(2015049)
文摘Six new transition metal complexes, [Zn（HBTC）（PYTPY）]n·n PYTPY（1）, [Cu（HBTC）（PYTPY）]n·n PYTPY（2）, [Co（HBTC）（PYTPY）]n·n DMF（3）, [Mn（HBTC）（PYTPY）]n·n DMF（4）, [Cd（HBTC）（PYTPY）（H2O）]n·2nH2O（5）, and [Co（HBTC）（PYTPY）（H2O）2]（6）,（H3BTC = 1,3,5-benzenetricarboxylic acid, PYTPY = 4＇-（4-pyridyl）-2,2＇：6＇,2＇＇-terpyridine, DMF = N,N？-dimethylformamide）, have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. Complexes 1~5 all feature one-dimensional chain structures, and complex 6 exhibits a zero-dimensional structure. Complexes 1~5 present three-dimensional（3D） supramolecular frameworks via π-π stacking interactions, whenas 6 has also a 3D supramolecular structure assembled by hydrogen bonding. Meanwhile, complexes 1 ~ 6 exhibit the thermal stabilities and photoluminescent properties.
基金financially supported by the 973 Program(No.2015CB654700 or 2015654702)the National Natural Science Foundation of China(Nos.51473156 and 51203147)
文摘Cobalt and nickel complexes （la-ld and 2a-2d, respectively） supported by 2-imidate-pyridine ligands were synthesized and used for 1,3-butadiene polymerization. The complexes were characterized by IR and element analysis, and complex la was further characterized by single-crystal X-ray diffraction. The solid state structure of complex la displayed a distorted tetrahedral geometry. Upon activation with ethylaluminum sesquichloride （EASC）, all the complexes showed high activities toward 1,3-butadiene polymerization. The cobalt complexes produced polymers with high cis-1,4 contents and high molecular weights, while the nickel complexes displayed low cis-l,4 selectivity and the resulting polymers had low molecular weights. The catalytic activities of the complexes highly depended on the ligand structure. With the increment of polymerization temperature, the cis-1,4 content and the molecular weight of the resulting polymer decreased.
基金This work was financially supported by the National Natural Science Foundation of China （Nos. 21571145 and 21633008）, the Fundamental Research Funds for the Central Universities and Large-scale Instrument and Equipment Sharing Foundation of Wuhan University.
文摘The development of efficient and stable non-noble metal-based electrocatalysts for the oxygen evolution reaction （OER） is one of the essential challenges for the upcoming hydrogen economy. Herein, three-dimensional （3D） mesoporous nickel iron selenide with rose-like microsphere architecture was directly grown on Ni foam via a successive two-step hydrotherrnal method. The unique 3D mesoporous rose-like morphology leads to a higher number of active sites as well as fast mass and electron transport through the entire electrode, and facilitates the release of 02 bubbles formed during the OER catalysis. As a result, the synthesized Ni0.76Fe0.24Se exhibits superior OER performances, with an ultralow overpotential of 197 mV needed to produce a current density of 10 mA.cm-2 in 1 M KOH, outperforming all transition metal selenide OER catalysts reported to date.
