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41.
NiSe Nanowire Film Supported on Nickel Foam: An Efficient and Stable 3D Bifunctional Electrode for Full Water Splitting 下载免费PDF全文
Chun Tang Ningyan Cheng Zonghua Pu Prof. Wei Xing Prof. Xuping Sun 《Angewandte Chemie (International ed. in English)》2015,54(32):9351-9355
Active and stable electrocatalysts made from earth‐abundant elements are key to water splitting for hydrogen production through electrolysis. The growth of NiSe nanowire film on nickel foam (NiSe/NF) in situ by hydrothermal treatment of NF using NaHSe as Se source is presented. When used as a 3D oxygen evolution electrode, the NiSe/NF exhibits high activity with an overpotential of 270 mV required to achieve 20 mA cm?2 and strong durability in 1.0 M KOH, and the NiOOH species formed at the NiSe surface serves as the actual catalytic site. The system is also highly efficient for catalyzing the hydrogen evolution reaction in basic media. This bifunctional electrode enables a high‐performance alkaline water electrolyzer with 10 mA cm?2 at a cell voltage of 1.63 V. 相似文献
42.
Kevin M. Arendt Prof. Abigail G. Doyle 《Angewandte Chemie (International ed. in English)》2015,54(34):9876-9880
A new substrate class for nickel‐catalyzed C(sp3) cross‐coupling reactions is reported. α‐Oxy radicals generated from benzylic acetals, TMSCl, and a mild reductant can participate in chemoselective cross‐coupling with aryl iodides using a 2,6‐bis(N‐pyrazolyl)pyridine (bpp)/Ni catalyst. The mild, base‐free conditions are tolerant of a variety of functional groups on both partners, thus representing an attractive C? C bond‐forming approach to dialkyl ether synthesis. Characterization of a [(bpp)NiCl] complex relevant to the proposed catalytic cycle is also described. 相似文献
43.
44.
Salt‐Free Reduction of Nonprecious Transition‐Metal Compounds: Generation of Amorphous Ni Nanoparticles for Catalytic C–C Bond Formation 下载免费PDF全文
Dr. Taiga Yurino Yohei Ueda Dr. Yoshiki Shimizu Dr. Shinji Tanaka Haruka Nishiyama Prof. Dr. Hayato Tsurugi Prof. Dr. Kazuhiko Sato Prof. Dr. Kazushi Mashima 《Angewandte Chemie (International ed. in English)》2015,54(48):14437-14441
A salt‐free procedure for the generation of a wide variety of metal(0) particles, including Fe, Co, Ni, and Cu, was achieved using 2,3,5,6‐tetramethyl‐1,4‐bis(trimethylsilyl)‐1,4‐diaza‐2,5‐cyclohexadiene ( 1 ), which reduced the corresponding metal precursors under mild conditions. Notably, Ni particles formed in situ from the treatment of Ni(acac)2 (acac=acetylacetonate) with 1 in toluene exhibited significant catalytic activity for reductive C? C bond‐forming reactions of aryl halides in the presence of excess amounts of 1 . By examination of high‐magnification transmission electron microscopy images and electron diffraction patterns, we concluded that amorphous Ni nanoparticles (Ni aNPs) were essential for the high catalytic activity. 相似文献
45.
Ivan Buslov Jeanne Becouse Simona Mazza Mickael Montandon‐Clerc Prof. Dr. Xile Hu 《Angewandte Chemie (International ed. in English)》2015,54(48):14523-14526
Chemoselective hydrosilylation of functionalized alkenes is difficult to achieve using base‐metal catalysts. Reported herein is that well‐defined bis(amino)amide nickel pincer complexes are efficient catalysts for anti‐Markovnikov hydrosilylation of terminal alkenes with turnover frequencies of up to 83 000 per hour and turnover numbers of up to 10 000. Alkenes containing amino, ester, amido, ketone, and formyl groups are selectively hydrosilylated. A slight modification of reaction conditions allows tandem isomerization/hydrosilylation reactions of internal alkenes using these nickel catalysts. 相似文献
46.
Regio‐ and Enantioselective Aza‐Diels–Alder Reactions of 3‐Vinylindoles: A Concise Synthesis of the Antimalarial Spiroindolone NITD609 下载免费PDF全文
Haifeng Zheng Prof. Dr. Xiaohua Liu Chaoran Xu Yong Xia Dr. Lili Lin Prof. Dr. Xiaoming Feng 《Angewandte Chemie (International ed. in English)》2015,54(37):10958-10962
An asymmetric aza‐Diels–Alder reaction of 3‐vinylindoles with isatin‐derived ketimines has been developed. A series of spiroindolone derivatives were thus obtained in good to excellent yields with excellent enantioselectivity (up to 96 % yield and 99 % ee). Furthermore, the antimalarial compound NITD609 could be obtained in three steps with an overall yield of 40.6 %. Control experiments and operando IR experiments imply a concerted reaction pathway. The regioselectivity and exo selectivity result from π–π interactions between the two indoline rings of the two reactants. 相似文献
47.
Svitlana Pukas Roman Gladyshevskii 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(11):996-1000
The crystal structure of Gd3Ni7Al14 (trigadolinium heptanickel tetradecaaluminide) belongs to a family of two‐layer structures and can be described as an assembly of interpenetrating centred straight prisms. For the Ni atoms, trigonal prisms (Al4Gd2 and Al6) are observed, the Al atoms are inside tetragonal (Ni2Al2Gd4, Ni2Al4Gd2, Al4Gd4, Ni4Al4 and Al8) and pentagonal (Ni4Al6 and Al10) prisms, while the Gd atoms are at the centres of pentagonal (Ni4Al6) and hexagonal (Ni4Al8) prisms. In each case, the true coordination polyhedron is a capped prism, also including atoms from the same layer. The structural features of Gd3Ni7Al14 are similar to those of the intermetallides PrNi2Al3 and ZrNiAl. In all these structures, Ni‐centred trigonal prisms form infinite columns via common triangular faces. The columns share prism edges and form a three‐dimensional framework with six‐membered rings in the (001) plane in the case of the PrNi2Al3 and ZrNiAl types. In the case of Gd3Ni7Al14, six‐membered rings are also observed, but only two‐thirds of the rings are interconnected via prism edges. 相似文献
48.
为了有效地从生物质衍生的乙酸中获得高氢气产率,通过水热法合成了一系列的NiMnY催化剂并用于乙酸自热重整(ATR)过程中,并采用X射线衍射(XRD)、N2吸附-脱附测试、H2程序升温还原(H2-TPR)探究催化剂中的内在联系。在Ni0.39Mn0.61YO3.11±δ催化剂中,经焙烧后形成了类钙钛矿型(Ni,Mn)YO3物相;经氢气还原后,转化为含有Mn O、Y2O3和高分散Ni纳米粒子的热稳定的Ni-Mn-Y-O物种。Ni0.39Mn0.61YO3.11±δ具有高效稳定的产氢催化性能,乙酸转化率高达100%,氢气产率达到2.68 mol_(H2)·molHAc-1。 相似文献
49.
在葡萄糖水溶液中合成得到平均粒径为5 nm的α-Ni(OH)2超微纳米粒子。研究结果发现,在水溶液中葡萄糖浓度能够控制α-Ni(OH)2纳米粒子粒径的大小,我们对其中的原理进行了剖析。当没有葡萄糖存在时,合成得到的Ni(OH)2晶型为β型,且颗粒粒径尺寸分布为微米级别。另外,研究发现α-Ni(OH)2超微纳米粒子室温下对中性水溶液中Li^+具有较强的吸附性能,且这种吸附性能随粒径的减小而剧烈增大;粒径为5 nm的α-Ni(OH)2粒子对Li^+的最大吸附量为214 mg·g^-1(远大于文献报道的有关吸附剂对Li^+的吸附容量),而粒径为1μm的β-Ni(OH)2在相同条件下对Li^+的最大吸附量低于30 mg·g^-1。计算分析表明,Li^+在α-Ni(OH)2纳米粒子表面吸附满足Freundlich方程,符合层层吸附模型。 相似文献
50.
以镍钴氢氧化物、异丙醇铝为原料,采用水解法合成三元前驱体Ni_(0.88)Co_(0.07)Al_(0.05)O_2,再与锂盐混合烧结得到正极材料(TEM)、X射线光电子能谱(XPS)、能量色散X射线谱(EDS)和恒电流充放电测试等对样品的晶体结构、微观形貌、元素价态以及电化学性能进行表征。研究表明,料液比1∶25、水洗3次、600℃回烧2 h合成的LiNi_(0.88)Co_(0.07)Al_(0.05)O_2具有较优的综合电化学性能,其在0.2C的放电比容量达207.6 mAh·g~(-1),首次充放电效率为84.8%,1C放电比容量为192.0 mAh·g~(-1),循环100周后,材料的放电比容量仍有148.0 mAh·g~(-1),容量保持率达到77.1%。 相似文献