Nickel-catalyzed cross-coupling reaction of alkynyl bromides with Grignard reagents

We describe a convenient method for the synthesis of 1,2-disubstituted acetylenes via a cross-coupling reaction of （bromoethynyl）benzene with Grignard reagents. The reaction of （bromoethynyl）benzene （1 mmol） with Grignard reagent （1.3 mmol） mediated by NiCl2 （4 mol%） and （p-CH3Ph）3P （8 mol%） in THF could produce 1,2-disubstituted acetylenes in good yields at room temperature.     

Catalytic performance of cement clinker supported nickel catalyst in glycerol dry reforming

The paper reports the development of cement clinker-supported nickel （with metal loadings of 5 wt%, 10 wt%, 15 wt% and 20 wt%） catalysts for glycerol dry （CO2） reforming reaction. XRF results showed that CaO constituted 62.0% of cement clinker. The physicochemical characterization of the catalysts revealed 32-folds increment of BET surface area （SBET） with the addition of nickel metal into the cement clinker, which was also corroborated by FESEM images. Significantly, XRD results suggested different types of Ni oxides formation with Ni loading, whilst Ca3SiO5 and Ca2Al0.67Mn0.33FeO5 were the main crystallite species for pure cement clinker. Temperature-programmed reduction analysis yielded three domains of H2 reduction peaks, viz. centered at approximately 750 K referred to as type-Ⅰ peaks, another peaks at 820 K denoted as type-Ⅱ peaks and the highest reduction peaks, type-Ⅲ recorded at above 1000 K. 20 wt% Ni was found to be the best loading with the highest XG and H2 yield, whilst the lowest methanation activity. Syngas with lower H2/CO ratios （0.6 to 1.5） were readily produced from glycerol dry reforming at CO2-to-Glycerol feed ratio （CGR） of unity. Nonetheless, carbon deposit comprised of whisker type （Cv） and graphitic-like type （Cc） species were found to be in majority on 20 wt%Ni/CC catalysts.     

镍基功能配合物的合成及电化学性质研究

在惰性气体的保护下,以无水甲醇为溶剂合成了两种以chxn(chxn=1(R),2(R)-环己二胺)为配体的镍配合物[NiIII(chxn)2Br]Br2和[NiⅡ(chxn)2]Br2,元素分析和红外光谱对其进行表征确定其组成。通过循环伏安法对镍的二价和三价配合物的电化学行为进行了研究,讨论了电极反应过程及其配体对不同价态中心离子氧化还原电势的影响,结果表明在甲醇介质中镍的二价配合物在铂电极上的电化学反应是准可逆过程,三价配合物在铂电极上的电化学反应是不可逆过程,循环伏安测试表明此类配合物能稳定Ni(Ⅲ)。     

CH4 reforming with CO2 for syngas production over La2O3 promoted Ni catalysts supported on mesoporous nanostructured γ-A12O3

Nanostructured -y-A12O3 with high surface area and mesoporous structure was synthesized by sol-gel method and employed as catalyst support for nickel catalysts in methane reforming with carbon dioxide. The prepared samples were characterized by XRD, N2 adsorption-desorption, TPR, TPO, TPH, NH3-TPD and SEM techniques. The BET analysis showed a high surface area of 204 m2.g-1 and a narrow pore-size distribution centered at a diameter of 5.5 nm for catalyst support. The BET results revealed that addition of lanthanum oxide to aluminum oxide decreased the specific surface area. In addition, TPR results showed that addition of lanthanum oxide increased the reducibility of nickel catalyst. The catalytic evaluation results showed an increase in methane conversion with increasing lanthanum oxide to 3 mol% and further increase in lanthanum content decreased the catalytic activity. TPO analysis revealed that the coke deposition decreased with increasing lanthanum oxide to 3 mol%. SEM and TPH analyses confirmed the formation of whisker type carbon over the spent catalysts. Addition of steam and Oxide to drv reformin feed increased the methane conversion and led to carbon free ooeration in combined orocesses.     

电化学方法制备石墨烯-铁氰化镍复合物及对抗坏血酸的电催化氧化研究

采用电化学还原方法制备了铁氰化镍-石墨烯复合薄膜电极,扫描电子显微镜(SEM)表征电还原石墨烯和铁氰化镍-石墨烯复合材料的表面形貌。采用循环伏安和计时电流技术研究了该修饰电极对抗坏血酸(AA)的电催化氧化性能,据此建立了一种测定AA的电化学分析新方法。由于石墨烯和铁氰化镍纳米颗粒之间的协同效应,使得该复合修饰电极对抗坏血酸具有优异的电催化活性。在0.1 mol/L pH 7.00的PBS溶液中,抗坏血酸的催化氧化电流与其浓度在1.0×10-4~7.0×10-4mol/L范围内呈良好的线性关系,检出限为3.1×10-5mol/L(S/N)。     

新型复合共沉淀法制备高能量/高功率型锂离子二次电池用5V正极材料LiNi_(0.5)Mn_(1.5)O_4及其电化学性能

在传统的固相法的基础上开发了新型复合共沉淀法制备LiNi0.5Mn1.5O4材料.新型复合共沉淀法采用(NH4)2CO3和(NH4)2C2O4共同作为沉淀剂,通过控制共沉淀反应条件,得到了具有均匀球形形貌的沉淀物颗粒.再通过与饱和氢氧化锂溶液的水热反应及高温反应,最终制备出具有球形次级形貌和纯相尖晶石结构的LiNi0.5Mn1.5O4材料.电化学测试表明,制备的LiNi0.5Mn1.5O4具有优异的电化学性能,其初始容量达到了141.4mAh·g-1.在0.3C、1C和3C倍率下经过200次循环后的容量分别为136.0 mAh·g-1(96.3%)、128.6 mAh·g-1(94.4%)和113.9 mAh·g-1(91.1%).通过高温反应及特殊的冷却处理,LiNi0.5Mn1.5O4在4.0 V低压区平台的容量损失得到了有效抑制.更重要的是,通过控制合成过程中的关键步骤,可实现半定量化控制材料结构中的原子有序排布程度,进而得到具有高能量密度和高功率密度的两种LiNi0.5Mn1.5O4材料,其能量密度和功率密度分别达到了648.6 mWh·g-1和7000 mW·g-1以上.     

基于MCM-41硬模板的镍铁磁性纳米管的合成及其磁性研究

以Si-MCM-41为硬模板,利用介孔材料的吸附作用,将Fe3+和Ni 2+按一定比例定量吸附组装到介孔材料的孔壁上;然后通过程序升温在900℃条件下高温焙烧,并经氢氟酸处理,得到直径大约为3.0nm的中空铁氧体纳米管.分别利用傅立叶变换红外光谱仪、扫描电镜、透射电镜、X射线衍射仪分析了合成材料的结构、组成、形貌;采用振动样品磁强计测定了其磁性能.结果表明,合成的镍铁氧体纳米管具有良好的管状形貌,其结构与分子筛MCM-41的结构相似,并具有良好的磁学性能.这说明MCM-41分子筛孔道结构具有可复制性,本研究可望为制备具有适当长径比的一维纳米磁性材料打下良好基础.     

异烟酸氮氧化物/磷钼酸镍络合物掺杂硅胶复合物的制备及其质子导电性(英文)

制备了异烟酸氮氧化物(简计为HINO)/磷钼酸镍有机-无机络合物({[Ni(H2O)8][H(H2O)2.5](HINO)4(PMo12O40)}n;简计为1)掺杂硅胶复合物(简计为1-SG1);采用红外光谱仪和X射线衍射仪证实了合成产物的结构.结果表明,化合物1的结构特征在1-SG1硅胶复合物中得以保留.与此同时,在约98%的相对湿度下,1-SG1在温度55~100℃范围内显示良好的导电性,其质子导电率达到8.98×10-3~1.03×10-2 S·cm-1;并且,在同等条件下,1-SG1的质子导电性优于化合物1.     

两种异马来二氰基二硫烯镍(II)-取代苄基喹啉鎓盐的制备及其光谱性质和晶体结构

以甲醇为溶剂,将异马来二氰基二硫烯酸钾[K2(i-mnt)]和六水氯化镍分别与溴化4-溴苄基喹啉盐([4-BrBzQl]Br)或溴化4-硝基苄基喹啉盐([4-NO2BzQl]Br)直接反应,得到两种新的离子对配合物[4-BrBzQl]2[Ni(i-mnt)2](1)和[4-NO2BzQl]2[Ni(i-mnt)2](2);测定了其红外光谱和紫外-可见光谱,并利用X射线衍射表征了配合物1的晶体结构.结果表明,配合物[4-BrBzQl]2[Ni(i-mnt)2]为三斜晶系,P-1空间群,其每个不对称单元含半个[Ni(i-mnt)2]2-阴离子和1个[4-BrBzQl]+阳离子,晶体中的阴、阳离子通过静电作用和C-H…S、C-H…N氢键作用形成网络结构.