过渡金属硫化物改性锂硫电池正极材料

锂硫电池(LSBs)由于单质硫正极具有超高能量密度(2600 Wh/kg)和超高理论比容量(1675 mAh/g),且环境友好、成本低廉,被认为是最有前景的储能体系之一。然而,硫正极的绝缘性和严重体积膨胀以及多硫化物(LiPSs)的“穿梭效应”等问题导致活性物质利用率低、循环稳定性差及电化学反应动力不足,严重阻碍了LSBs的商业化发展。最新研究表明,过渡金属硫化物作为载体或添加剂能够显著改善LSBs正极材料的电化学性能。本文从等效/共正极作用、导电性增强作用、LiPSs吸附作用和电化学反应催化作用四个方面梳理了过渡金属硫化物在LSBs正极材料中的改性机理,并指出多元过渡金属硫化物复合﹑纳米结晶和量子化作为增加比表面积和活性位点的方法是过渡金属硫化物用于锂硫电池正极材料的重要发展方向,可大幅提升LSBs的电化学性能。     

Cobalt(II) Salen Complex with Two Aza-crown Pendants and Its Analogues as Synthetic Oxygen Carriers

Introduction Synthetic oxygen carriers1 are of great interest as models to mimic oxygen carrying metalloenzymes2 for oxygen storage and transport. The cobalt(II) complexes of Schiff bases, such as Salen and its analogues, have been the first and the most extensively investigated due to their structural similarity to those found in biological systems.3,4 However, these complexes are easy to dimerize and lose activities after oxygen molecule ab-sorption.5 Avdeef and coworkers6 demonstrated tha…     

Synthesis, structural characterisation and thermal decomposition studies of some 2,4′-bipyridyl complexes with cobalt(II), nickel(II) and copper(II)

2,4-Bipyridyl (2,4-bipy orL) complexes with cobalt(II), nickel(II) and copper(II) of the formulae M(2,4-bipy)₂(CH₃COO)₂·2H₂O (M(II) = Co, Ni, Cu), Co(2,4-bipy)₂SO₄·3H₂O or Ni(2,4-bipy)₂SO₄·4H₂O have been prepared and their IR and electronic (VIS) spectra are discussed. The thermal behaviour of the obtained compounds has also been studied. The intermediate products of decomposition at different temperatures have been characterized by chemical analysis and X-ray diffraction.We thank dr. A. Malinowska for performing VIS spectra. This work was supported by the KBN project No. PB 0636/P3/93/04.     

Synthetic Methodologies and Structures of Metal-[C60]Fullerene Complexes

A review of the chemistry of transition metal-[C₆₀]fullerene complexes is presented. The main focus is directed toward the different methodologies for obtaining both metal bound and ligand bound complexes of C₆₀, and the different types of structures which have been so far identified for metal-C₆₀ complexes.     

气相中Y＋, Zr＋, Nb＋与CO2反应的理论研究

以Y^＋, Zr^＋, Nb^＋与CO₂反应作为第二前过渡金属离子与CO₂反应的范例体系. 采用密度泛函UB3LYP方法, 对于Y, Zr, Nb采用Stuttgart赝势基组, 对于CO₂采用6-311＋G(2d)基组, 计算研究了三种金属离子在基态和激发态时与CO₂气相反应的机理. 结果表明三种金属离子与CO₂反应以高自旋进入反应通道, 在反应过程中发生系间窜越, 以低自旋中间体和最终产物离开反应通道. 用内禀坐标单点垂直激发计算的方法找到了势能面交叉点, 并作了相应的讨论. 因为有金属离子的参与, 使单分子CO₂的强吸热分解反应变为生成CO和MO^＋的放热过程.     

The Activation and Carbonylation of the C-Cl Bond Catalyzed by Transition-Metal Complexes

Thecarbonylationoforganichalides,catalyzedbytransition-metalcomPlexes,isareactionofindustrialinterestleadingtoawiderange0fproductslilieesters,aldehydes,awhdesandacids.Formanyyears,catalyticactivationandfunctionalisationofthecarbonthalogenbondsinorganichalideshavebeenoneofthemostchallengingproblemsanddesirablegoalsforchendsts.Oforganichalides,0rgancchlorideisthemodrmaforeundiDexPdrieerefD1thepeDfu3efulboinboLalindusny.However,because0ftheinertness0ftheirC-Clbonds,organicchloridesexhibitl0wre…     

反相微乳法合成稀土六铝酸盐催化剂及其甲烷催化燃烧研究

天然气发电由于其建设周期短,扩容简单,投资小,且产生的二氧化碳在所有矿物燃料中最少,温室效应小,在电力生产中会越来越受到重视[1].二十世纪70年代,Pfefferle[2]等人提出了天然气催化燃烧方法,可降低反应温度(通常降为1 200～1 400 ℃),使甲烷在较低的浓度下完全燃烧,不但能使NOx和CO降低,减少污染,而且还能提高能效,节约宝贵的燃料资源.……     

Ruthenium(II)‐Catalyzed C−H Activation of Imidamides and Divergent Couplings with Diazo Compounds: Substrate‐Controlled Synthesis of Indoles and 3H‐Indoles

Indoles are an important structural motif that is commonly found in biologically active molecules. In this work, conditions for divergent couplings between imidamides and acceptor–acceptor diazo compounds were developed that afforded NH indoles and 3H‐indoles under ruthenium catalysis. The coupling of α‐diazoketoesters afforded NH indoles by cleavage of the C(N₂)?C(acyl) bond whereas α‐diazomalonates gave 3H‐indoles by C?N bond cleavage. This reaction constitutes the first intermolecular coupling of diazo substrates with arenes by ruthenium‐catalyzed C?H activation.     

One‐Step Electrodeposition of NiCo2S4 Nanosheets on Patterned Platinum Electrodes for Non‐Enzymatic Glucose Sensing

The preparation of NiCo₂S₄ (NCS) nanosheets on photolithographically patterned platinum electrodes by electrodeposition was explored. The as‐prepared nanosheets were systematically characterized by field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and X‐ray photoelectron spectroscopy techniques. The NCS‐modified Pt electrode was used as a non‐enzymatic glucose sensor. The sensor response exhibited two linear regions in glucose concentration, with a limit of detection of 1.2 μm . The sensors showed that the as‐prepared NCS nanosheets have excellent electrocatalytic activity towards glucose with long stability, good reproducibility, and excellent anti‐interference properties, and thus, this material holds promise for the development of a practical glucose sensor.