首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 203 毫秒
1.
大庆减压渣油热转化前后镍分布的研究   总被引:3,自引:1,他引:3  
大庆减压渣油在高压釜中 4 0 5℃、1h条件下进行热转化反应 ,对原料及热转化后尾油 (>5 0 0℃ )用正戊烷沉淀沥青质 ,再用含水 5 % (质量分数 )的氧化铝为吸附剂的色谱法将大庆减压渣油分离为六个组分 ,然后用硅胶色谱法对每个组分中的镍卟啉进行富集 ,并根据可见光谱加以测定。用原子吸收法测定了原料减压渣油、尾油及各组分的镍含量。研究结果表明 ,大庆减压渣油经过热转化后有近 5 0 %的渣油转化为气体和馏分油 ,并有少量的焦炭生成。大庆减压渣油无戊烷沥青质 ,其中的Ni主要集中在中胶、重胶及n C5沥青质中。在热转化尾油中 ,大部分的镍集中在中胶、重胶及戊烷沥青质中 ,卟啉镍主要集中在多环芳烃和轻胶质中 ,非卟啉镍主要集中在中胶、重胶和戊烷沥青质中。热转化对镍起到了脱除作用  相似文献   

2.
本研究通过临氢热解方法处理委内瑞拉减压渣油沥青质,通过电感偶合等离子体质谱仪(ICP MS)、紫外-可见光光谱仪(UV-vis)、高温气相色谱-原子发射检测器联用仪(HT GC-AED)和傅里叶变换离子回旋共振质谱(FT-ICR MS)等手段分析表征反应产物,探究沥青质的分子组成与结构,以及镍和钒化合物的存在形态。实验结果表明,随着临氢热解反应温度从330℃升高至410℃,反应产物的甲苯可溶物收率由64%下降至19%,可被GC-AED检测到的镍、钒化合物的含量大幅度升高,镍和钒卟啉的分子组成分布也随反应温度的升高呈现出规律性的变化。  相似文献   

3.
以气相色谱为主要手段, 配合Mossbauer波谱、X射线衍射等方法研究了草酸铁(III)与硝酸钠在氢气氛中的固相反应, 实验结果表明: 240℃前两者不发生反应, 草酸铁(III)还原分解; 260-320℃固相间发生强烈氧化还原反应, 大量二氧化碳放出, 并伴有少量氧和一氧化氮, 380℃后, 生成的亚硝酸钠与未反应的硝酸钠在铁(III)化合物作用下, 提前分解, 同时铁(III)化合物转化成γ-Fe2O3.  相似文献   

4.
水溶性卟啉催化氧化1,5-萘二酚   总被引:1,自引:0,他引:1  
合成并表征了系列水溶性卟啉配体[H2TPPS: 5,10,15,20-四-(4-磺酸基苯基)-21H,23H-卟啉, H2TMPyP: 5,10,15,20-四(4-吡啶基)-21H,23H-卟啉, H2TCPP: 5,10,15,20-四-(4-羧基苯基)-21H,23H-卟啉]及相应的铁、锌及钴配合物. 将水溶性卟啉作为光敏剂, 用于1,5-萘二酚的光催化反应, 产物为5-羟基-1,4萘醌. 利用UV-Vis方法对卟啉催化1,5-萘二酚的反应过程进行了监测, 探索了水相和水/二氯甲烷双相催化体系, 确定了较为理想的反应条件. 探讨了不同取代基和不同金属离子对卟啉催化性能的影响, 初步讨论了催化机理. 结果表明, 具有磺酸根阴离子取代基的水溶性卟啉具有最好的催化活性; 卟啉的催化活性与其在反应体系中的稳定性密切相关; 铁卟啉在反应初期呈现很高的催化活性, 但在光照条件下容易发生光解而导致催化活性的降低; 无金属的磺酸卟啉在催化体系中的催化活性和稳定性最好.  相似文献   

5.
为了制备2-取代卟啉,研究了2-硝基-5,10,15,20-四苯基卟啉1及其镍2,铜3,锌4配合物与2-萘酚钠在不同溶剂中的反应。在2-萘酚中,150℃的温度下反应,分别得到2-(2-萘酚)-5,10,15,20-四苯基卟啉5 (72%), 及其镍(II) 6(78%), 铜(II) 7(81%), 锌(II) 8(65%)配合物。在其它质子性溶剂如一缩二乙二醇和一缩二乙二醇单甲醚中反应,得到相同的产物。当在非质子性溶剂DMF,150 ℃的温度下反应,除了得到5 (70%),6 (34%),7 (54%), 8 (50%)外,还分别得到微量2-(2-萘氧基)-5,10,15,20-四苯基卟啉9, 及其镍(II) 10(40%),铜(II) 11(18%), 锌(II)12 (2%)配合物。但室温下,无论用DMF还是DMSO做溶剂,均只得到5,6,7,8。卟啉1-4与萘酚钠的反应比与苯酚钠反应快,C-C键产物5-8的形成被认为是通过SRN1机理进行的。  相似文献   

6.
用紫外-可见光谱研究了钴(II)、镍(II)、锌(II)的1, 1, 1, 5, 5, 5-六氟-2, 4-戊二酮-二水配合物[M(hfac)2(H2O)2, M=Co、Ni、Zn]与5, 10, 15, 20-四(五氟苯基)卟啉[H2tpfpp]在超临界二氧化碳中反应生成金属卟啉[M(tpfpp)]的反应动力学. 在金属配合物大大过量时, 反应对卟啉为一级. 其表观一级速率常数随钴(II)、镍(II)配合物的浓度增加先增加、而后趋于稳定, 而表观一级速率常数随锌(II)配合物的浓度增加线形增加. 根据实验事实, 讨论了反应的机理, 得到了相应的热力学和动力学参数.  相似文献   

7.
本文报道了五种5,15-二(对-取代苯基)-2,8,12,18-四乙基-3,7,13,17-四甲基卟啉(Ⅱa—Ⅱe)和五种5,15-二(对-取代苯基)-2,3,7,8,12,13,17,18-八甲基卟啉(Ⅰa—Ⅰe)以及它们的铜、铁、镍金属配合物的合成。这些化合物的结构均经元素分析、UV、~1HNMR和MS鉴定。芳环上不同取代基对卟啉成环反应有一定影响,拉电子基团有利于反应。其顺序如下:NO_2>H>CH_3>OCH_3>N(CH_3)_2。  相似文献   

8.
用紫外-可见光谱研究了钴(II)、镍(II)、锌(II)的1,1,1,5,5,5-六氟-2,4-戊二酮-二水配合物[M(hfac)2(H2O)2,M=Co、Ni、Zn]与5,10,15,20-四(五氟苯基)卟啉[H2tpfpp]在超临界二氧化碳中反应生成金属卟啉[M(tpfpp)]的反应动力学.在金属配合物大大过量时,反应对卟啉为一级.其表观一级速率常数随钴(II)、镍(II)配合物的浓度增加先增加、而后趋于稳定,而表观一级速率常数随锌(II)配合物的浓度增加线形增加.根据实验事实,讨论了反应的机理,得到了相应的热力学和动力学参数.  相似文献   

9.
设计合成了两类具有π共轭骨架的Salen-卟啉型配体及金属配合物. 以Salen-卟啉半体及相应的醛为原料, 运用金属模板法合成了单核镍和双核镍Salen-卟啉型金属配合物. 在单核镍的基础上可得到异双核镍、锌Salen-卟啉型金属配合物. 通过核磁共振氢谱(1H NMR)、紫外-可见(UV-Vis)光谱、傅里叶变换红外(FTIR)光谱、电喷雾质谱(ESI-MS)和荧光光谱等多种谱学手段对其结构进行了表征. 研究表明, 单核镍及异双核镍、锌配合物中, 镍离子落入Salen 部分的配位空腔, 而锌离子则是与卟啉部分形成锌卟啉大环结构。由于卟啉环流效应及分子π共轭结构的影响, 导致配体上的氢原子的化学位移向高场或低场移动. 当金属离子与配体配位之后,卟啉部分的紫外-可见光谱的Soret带和Q带均发生显著变化, 而荧光则出现猝灭现象.  相似文献   

10.
以镍网(NM)为基体,采用氢气泡模板法合成了独立分相金属Ni、Cu为主晶相、具有四级复合微纳结构的镍铜合金电催化剂(NiCu/NM)。在电催化析氢(HER)及肼氧化(HzOR)反应中,NiCu/NM表现出优良的催化活性,在1.0 mol·L^-1KOH(含0.5 mol·L^-1N2H4·H2O)溶液中,电流密度为10 mA·cm^-2时,其需要的HER及HzOR过电势分别为104和41 mV;在双电极体系中,电流密度为100 mA·cm^-2时,NiCu/NM的分解槽压仅为0.536 V,远低于全水分解过程所需的1.921 V,大大提高了电池的产氢效率。无论三电极体系还是双电极体系,NiCu/NM均表现出优异的催化活性及稳定性。分析认为,镍铜合金薄膜的多级复合结构使其展现出增大了近14倍的电化学活性面积(ECSA),为电催化反应提供了大量催化活性位点,也为电极表面的电荷传输、物质传递提供了充足的通道;Cu的掺入提高了材料的本征HER活性,两者协同促进了电催化活性的提升,其中NiCu/NM的结构优势对其优良的催化性能起主导作用。  相似文献   

11.
1 INTRODUCTION The ability of dialkyldithiocarbamate anion, -S2- CNR2 (dtc) ligand, to bind metal has been known for many years[1, 2]. It forms a chelate with virtually all transition elements and is proven to be a versatile chelating agent for the separation and extract of metals in analytical chemistry and mineral floa- ting[3~5]. Water soluble dialkyldithiocarbamate com- plexes have been tested in various medical appli- cations[6]. Some of substituted dithiocarbamate salts also show …  相似文献   

12.
Several nickel complexes [N,N]NiBr2, in which IN,N] indicates bidentate nitrogen-containing ligands (1: [N,N]=N-(2,6-diisopropylphenyl)pyridine-2-carboxaldimine (Cl8H22N2); 2: N-(2,6-diisopropylphenyl)-6-methylpyridine-2-carboxaldimine (C19H24N2); 3: N-(2,4,6-trimethylphenyl)pyridine-2-carboxaldimine(Cl5Hl6N2); 4: N-(2,4,6-trimethylphenyl)-6-methylpyridine-2-carboxaldlmlne (Cl6Hl8N2) were synthesized. Some of the nickel complexes exhibit high activity for ethylene oligomerization in the presence of an organoaluminum activator. The main factor affecting the activity and the structure of oligomers is the steric effect of substituents on [N,N] ligands. Methylaluminoxane (MAO) -activated catalysts showed higher activities and produced oligomers with higher molecular weight than Et2AlCl-activated ones. The oligomerization in toluene rather than hexane results in much higher activity, and the oligomers produced in toluene have relatively high molecular weight. With activation of MAO or Et2AlCl,the [N,N]NiBr2 system tended to produce highly branched oligomers with low α-olefin content, but the α-olefin content could be increased by changing the reaction conditions.  相似文献   

13.
1 INTRODUCTION Schiff base complexes containing sulfur and com- plexes of amino acid Schiff bases[1~5] have recently aroused increasing interest because of their antiviral, anticancer and antibacterial activities. Taurine, an amino acid containing sulfur, is indispensable to human beings and has important physiological func- tions. Recently, we have found that the Shiff base derived from taurine has manifold coordination modes[4~10]. Aromatic-ring stacking interaction is an important …  相似文献   

14.
The C?H thiolation of aniline derivatives was accomplished with a versatile nickel(II) catalyst under ligand‐free conditions. The robust nature of the nickel catalysis system was reflected by the C?H thiolation with a good functional group tolerance and an ample scope, employing anilines possessing removable directing groups. The widely applicable nickel catalyst also allowed for aniline C?H selenylations, while mechanistic studies provided strong support that the rate‐determining step is the C?H activation.  相似文献   

15.
标题配合物是由三齿配体N, N-二(2-苯并咪唑亚甲基)胺(IDB)、Ni(ClO4)2·6H2O与水杨酸钠在乙醇溶液中反应得到的紫色晶体。用X-射线衍射测定了其单晶结构。结果表明,该晶体属三斜晶系,P 空间群,化学式:C41H43ClN10NiO9,Mr = 914.01,a = 11.010(2),b = 13.800(3),c = 15.550(3) 牛 = 100.75(3),?= 102.97(3), = 107.56(3)? V = 2111.3(7) ?,Z = 2,F(000) = 952,Dc = 1.438 g/cm3,(MoK) = 0.591 mm-1,8215个独立可观测点(I>2(I))。最终偏离因子R(I>2(I)):R = 0.0591, wR = 0.1325;R(全部数据): R = 0.1302,wR = 0.1572。结构分析表明,镍(Ⅱ)分别与2个IDB配体中的苯并咪唑的4个氮和胺基的2个氮配位形成畸变的八面体构型。  相似文献   

16.
焙烧温度对NiO/δ-Al2O3催化剂性能的影响   总被引:6,自引:0,他引:6  
应用XRD,TPR,H2-TPD技术研究焙烧温度对NiO/δ-Al2O3催化剂性能的影响。结果表明,随着焙烧温度的增高,NiO与载体Al2O3之间相互作用逐渐增强,直至最后生成NiAl2O4尖晶石。同时表明,随着焙烧温度的提高,催化剂的还原温度明显增高。另外,TPR结果还表明NiAl2O4仅仅是与载体发生强相互作用的那部分NiO进一步进入Al2O3晶格的结果,而游离态的NiO不参与形成NiAl2O  相似文献   

17.
合成了标题化合物。该化合物的分子式[Ni(C5H5N)2(C7H6O2N)2]H2O(C24H24N4NiO3),分子量475.18,采用单色的MoKα (λ = 0.71073 )射线测定,共收集7408个数据,其中独立衍射点2567个(Rint = 0.0272),I > 2s(I)可观测点数1926个,结果表明该化合物属单斜晶系, 空间群C2/c其晶胞参数为: a = 14.466(2),b = 12.193(2),c = 14.072(2) ;β = 116.229(2)°,V = 2226.6(5) 3,Z = 4,Dc = 1.418 g/cm3 ,μ = 0.905 mm-1,F(000) = 992. 2个水杨醛亚胺各提供2个配位原子参与配位,2个吡啶各提供1个配位原子参与配位,该配合物是六配位的八面体构型,同时讨论了该体系中不同配位原子的配位能力的差异。  相似文献   

18.
In this paper dry reforming of methane (DRM) was carried out over nanocrystalline MgAl2O4-supported Ni catalysts with various Ni loadings. Nanocrystalline MgAl2O4 spinel with high specific surface area was synthesized by a co-precipitation method with the addition of pluronic P123 triblock copolymer as surfactant, and employed as catalyst support. The prepared samples were characterized by X-ray diffraction (XRD), N2 adsorption, H2 chemisorption, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), temperature- programmed desorption (TPD) and transmission and scanning electron microscopies (TEM, SEM) techniques. The obtained results showed that the catalyst support has a nanocrystalline structure (crystal size: about 5 nm) with a high specific surface area (175 m2 g-1) and a mesoporous structure. Increasing in nickel content decreased the specific surface area and nickel dispersion. The prepared catalysts showed high catalytic activity and stability during the reaction. SEM analysis revealed that whisker type carbon deposited over the spent catalysts and increasing in nickel loading increased the amount of deposited carbon. The nickel catalyst with 7 wt% of nickel showed the highest catalytic activity.  相似文献   

19.
A method for direct synthesis of tetrasubstituted fluoroarenes via nickel‐catalyzed [2+2+2] cycloaddition is presented. The reaction combines one molecule of 1,1‐difluoroethylene with two molecules of alkynes and involves sequential cleavage of the C?F and C?H bonds in difluoroethylene. The catalytic cycle is established by reduction of the intermediary NiII fluoride with a triethylborane‐based borate.  相似文献   

20.
A nickel nanowire catalyst was prepared by a hard template method,and characterized by transmission electron microscopy (TEM),N2 physical adsorption,X-ray photoelectron spectrometry (XPS),X-ray diffraction (XRD) and H2 temperature-programmed reduction (H2-TPR).The catalytic properties of the nanowire catalyst in the partial oxidation of methane to syngas were compared with a metallic Ni catalyst which was prepared with nickel sponge.The characterization results showed that the nickel nanowire catalyst had high specific surface area and there was more NiO phase in the nickel nanowire catalyst than in the metallic Ni catalyst.The reaction results showed that the nickel nanowire catalyst had high CH4 conversion and selectivities for H2 and CO under low space velocity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号