双功能催化剂Nix/MgyAl2O y+3用于丁酮烷基化反应

以Nix/zMgy/zAl2/z(OH)2(CO3)1/z(z=x+y+2,x=0.2、1,5≤y≤11.8)水滑石为前驱体,经高温焙烧和H2还原后得到了一系列可用于甲醇-丁酮(MEK)烷基化反应的Nix/MgyAl2Oy+3(x=0.2、1,5≤y≤11.8)双功能催化剂,并采用X射线衍射(XRD)、透射电子显微镜(TEM)、程序升温还原(TPR)、程序升温脱附(TPD)等技术对催化剂的结构和形貌进行了表征。活性实验结果发现Ni/Mg9Al2O12催化剂具有较好的活性,在常压、温度280℃、原料液时空速(LHSV)6.0 h-1的条件下,丁酮的转化率为61.6%,3?戊酮(DEK)和3?甲基?2?丁酮(MIPK)的选择性分别为45.0%和17.7%。表征结果表明催化剂中合适的活性金属Ni和MgO含量对提高DEK和MIPK的选择性具有重要的影响,Ni与催化剂表面碱量之间的协同作用可能是影响催化剂的活性和选择性的主要因素。     

配位聚合物[Ni(cpna)(bpy)(H2O)]n的合成、晶体结构及磁性质

通过水热方法,采用H₂cpna(H₂cpna=5-(2′-carboxylphenyl))和bpy(bpy=2,2′-bipyridine)与Ni(OAc)₂·4H₂O反应,合成了一个具有二维结构的配位聚合物[Ni(cpna)(bpy)(H₂O)]_n (1),并对其结构和磁性质进行了研究。结构分析结果表明该聚合物的晶体属于单斜晶系,P2₁/c空间群。3个镍(Ⅱ)离子、3个cpna配体、3个2,2′-bpy配体和3个配位水分子形成了一个[Ni₃(cpna)₃(bpy)₃(H₂O)₃]环,这些环通过镍(Ⅱ)离子与cpna配体的配位作用形成了一个二维层状结构。层与层之间又通过π-π堆积作用形成了一个三维的配位框架。研究表明,该聚合物中相邻镍(Ⅱ)离子之间存在很弱的反铁磁相互作用。     

柠檬酸对Ni2P/TiO2-Al2O3催化剂加氢脱硫性能的影响

采用溶胶-凝胶法制备了TiO2-Al2O3复合载体,以柠檬酸(CA)为络合剂采用浸渍法制备了Ni2P负载的TiO2-Al2O3复合载体催化剂,并用X射线衍射(XRD)、N2吸附比表面积测定、H2程序升温氢还原(H2-TPR)、程序升温氧化(TPO)、X射线光电子能谱(XPS)技术对催化剂的结构和性质进行了表征,考察了CA/Ni摩尔比对在Ni2P/TiO2-Al2O3催化剂上进行的二苯并噻吩(DBT)加氢脱硫(HDS)性能的影响.结果表明:适量的CA可以丰富催化剂的孔道,提高催化剂的比表面积.当n(CA)/n(Ni)=2:1时,催化剂的比表面积达到126.75m2·g-1,与不加CA时相比,提高了57.05m2·g-1.调节n(CA)/n(Ni)能够改善活性相的分布,改变活性相的种类;引入CA使Ni和P前驱体的还原温度明显降低,促进活性相Ni2P的生成,一定程度上能够抑制催化剂表面炭的形成和沉积,提高其稳定性.n(CA)/n(Ni)=2:1时,催化剂具有最好的加氢脱硫活性,在360°C,3.0MPa,氢油比为500(V/V),液时体积空速为2.0h-1的条件下,二苯并噻吩转化率为99.5%,可将模拟油中硫含量由2%(w)降低到0.01%(w).     

从大木尺度现象看柳林香严寺毗卢殿建造年代之复杂性*

采用共沉淀法制备了高分散80%Ni/Al_2O_3催化剂,经350℃焙烧,得高分散NiO/Al_2O_3(NiO粒径～3 nm),将其以CS_2硫化(310℃, 4 h)或PPh_3磷化(320℃, 36 h),分别获得了高分散的硫化镍(Ni_3S_2和Ni_3S_4, 5.8 nm)和Ni_2P(7.0nm),在二苯并噻吩(DBT)的加氢脱硫(HDS)反应中, Ni_2P的活性远高于NiS_x(360℃时DBT的转化率分别为100%和75%).若将NiS_x用PPh_3磷化,则NiS_x全部转化为Ni_2P(13.3 nm),其HDS活性远高于原来的NiS_x且与直接磷化获得的Ni_2P(7.0 nm)相当.反之,若将Ni_2P用CS_2硫化,则Ni_2P物相不变,粒径也没有长大,表明Ni_2P物相远比NiS_x稳定,且其HDS活性高于直接磷化的Ni_2P,表明其Ni_2P表面可能生成了HDS活性更高的某种Ni-P-S物种.     

新型笼状同多钒酸盐[Ni(1,10′-phen)3]2·[V2ⅣV8ⅤO26]的水热合成和晶体结构

尽管多金属氧酸盐(POMs)的研究已有180多年的历史, 但大量的POMs结构在最近几十年才被陆续解析出来[1～4].     

MoqRuyXz(X=S，Se，Te)纳米簇电催化还原氧的性能对比研究

直接甲醇燃料电池存有两个较为突出的技术问题,即:阳极催化剂活性低和甲醇渗透[1～4]。针对“甲醇渗透”(cross-over)问题有两种解决途径:一、使用低甲醇渗透率电解质膜(阻醇膜),二、使用抗甲醇氧还原电催化剂[4]。目前,多数改性或新型膜材料的阻醇率有一定提高,然而膜的电导率等指标不够理想[5～7]。抗甲醇氧还原催化材料的开发研究正逐渐受到重视[4]。因过渡金属纳米簇硫族化合物电催化剂的活性、抗甲醇性、稳定性高、成本低逐渐得到青睐,是有竞争力的Pt替代催化材料[7～15]。过渡金属纳米簇硫族化合物MqM′yXz的金属核M′多为Ru,掺杂…     

三维超分子[Ni(hmt)2(SCN)2(H2O)2][Ni(SCN)2(H2O)4](H2O)2的自组装,晶体结构及磁性质(hmt=六次甲基四胺)

Compound [Ni(hmt)₂(SCN)₂(H₂O)₂][Ni(SCN)₂(H₂O)₄](H₂O)₂ (hmt=hexamethylenetetramine) was pre-pared and structurally characterized by means of X-ray single crystal diffraction. The two neutral units [Ni(hmt)₂(SCN)₂(H₂O)₂] and [Ni(SCN)₂(H₂O)₄] are joined together through hydrogen bonds N…H-O, O…H-O and S…H-O. In the solid state, the compound has three-dimensional network structure. The determination of its variable-temperature magnetic susceptibilities (5～300K) shows that the magnetic behavior obeys the Curie-Weiss law over the whole temperature ranges.     

Two Novel Oxamidato-bridged Tetranuclear Complexes M[Cu(PMoxd)]3(ClO4)2 (M=Mn, Ni, Cu(PMoxd)=N,N′-bis(pyridyl-methyl)-oxamidatocopper(II)): Syntheses, Spectra, Magnetic and Electrochemical Properties

Two novel oxamidato-bridged Mn[Cu(PMoxd)]₃(ClO₄)₂ (1) Ni[Cu(PMoxd)]₃(ClO₄)₂ (2) tetranuclear complexes were prepared and characterized by i.r., e.p.r., electronic spectra, cyclic voltammograms, and magnetic properties. The magnetic analysis was carried out by means of the theoretical expression of the magnetic susceptibility deduced from the spin Hamiltonian H=−2JS_M(S_Cu1+ S_Cu2 + S_Cu3) (M=Mn, Ni), leading to J=−20.4 cm⁻¹; −121.1 cm⁻¹ for complexes (1) and (2) respectively. Magnetic measurements indicate that the overall magnetic behavior of the tetranuclear species are antiferromagnetic.     

Effect of Iron Substitution on the Structural, Electric, and Magnetic Properties inR-Type PbFexV6−xO11, a Frustrated System

Single-phase material of the solid solution PbFe_xV_6−xO₁₁was prepared by solid-state reaction over the range 1≤x≤1.75. Powder preparations of PbV₆O₁₁, however, were always accompanied by a small amount of impurity. The noncentrosymmetric space groupP6₃mcof PbV₆O₁₁, which has anR-block structure, remains unchanged with iron substitution. The crystal structure of PbFe_1.75V_4.25O₁₁was refined from single-crystal X-ray data toR=0.049. The iron atoms are located preferentially in specific crystallographic sites. The triangular–bipyramidal site is completely occupied by Fe³⁺while the interstices of the central octahedral layer are solely occupied by the vanadium V(1) atoms. The other two crystallographic sites have mixed Fe/V occupancies. Magnetic measurements performed on nearly single-phase PbV₆O₁₁and the iron substituted phases reveal a spin-glass-type behavior with freezing temperaturesT_fof 50 and 65 K, respectively.T_fis independent of the iron ratio. This spin-disordered system is attributed to strong frustration occuring in thea–bplane because of the existence of V(1) trimers providing alternatively long and short V–V distances along theaaxis. Resistance and Seebeck coefficient measurements indicatep-type conduction aboveT_fwhile the system becomes an insulator belowT_f. Fe³⁺ions do not participate in the hopping process, and they block conduction parallel to thecaxis because of their location in the bridging dimeric octahedral and bipyramidal sites.     

Electronic structure of magnetic semiconductors Cd1 ? xMnxGeAs2 and Cu1 ? xMnxGaTe2

The band structures of pure semiconductors CdGeAs₂ and CuGaTe₂, as well as magnetic semiconductors Cd_{1 − x} Mn _x GeAs₂ and Cu_{1 − x} Mn _x GaTe₂ (x = 0.0625), have been calculated by the density functional theory method. In both compounds, the Mn3d orbitals form a narrow band near the Fermi level. In the case of Cd_{1 − x} Mn _x GeAs₂, the Mn3d orbitals are slightly involved in chemical bonding. In the case of Cu_{1 − x} Mn _x GaTe₂, the same orbitals are considerably involved in chemical bonding. The relationship of these results with the properties of the compounds and ferromagnetism models is discussed. Original Russian Text ? S.V. Murashov, V.G. Yarzhemsky, V.I. Nefedov, E.N. Murav’ev, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 8, pp. 1327–1331.     

二维层状结构十钒酸盐[K(H2O)2Ni(H2O)6]2[V10O28]的合成及性质(英)

A novel heteropoly compound, containing two kinds of coordinated cations, [K(H₂O)₂Ni(H₂O)₆]₂[V₁₀O₂₈], has been synthesized through routine process and characterized by elemental analyses, IR, ⁵¹V NMR and single crystal X-ray diffraction. It crystallizes in the triclinic system, space group P1 with a=0.87382(17) nm, b=1.075 4(2) nm, c=1.111 1(2) nm, α=65.10(3)°, β=75.01(3)°, γ=70.63(3)°, V=0.884 8(3) nm³ and Z=1. The X-ray analysis reveals that the two kinds of coordinated cations are linked by three shared coordinated water molecules, and K⁺ cations coordinate with ten oxygen atoms: five of which come from V₁₀O₂₈^6- anion, the other five from water molecules. The title compound exhibits extended 2D array building up of V₁₀O₂₈^6- groups connected by ten-coordinated K⁺ cations. The hexahydrated nickel cations Ni(H₂O)₆²⁺ lie in neat apposition to three adjacent V₁₀O₂₈^6- clusters. CSD: 413271.     

一维链状镍(Ⅱ)配合物[Ni(L)(Mf)]n的合成、晶体结构及电化学性质

合成了1个含2-羟基苯乙酮缩水杨酰腙(H₂L)和单齿N-杂环分子吗啡啉(Mf)的镍(Ⅱ)配合物[Ni(L)(Mf)]_n,并通过元素分析、紫外光谱、热分析以及单晶衍射等手段进行表征。在配合物中,中心Ni(Ⅱ)与酰腙配体的酚氧、亚胺氮、去质子酰胺氧原子以及中性吗啡氮原子配位形成平面四方形的N₂O₂配位构型。配合物通过N-H(吗啡)…O(吗啡)分子间氢键作用构筑成一维超分子网络结构。采用循环伏安法研究了化合物的电化学性质。     

Synthesis of continuous substitutional solid solutions M1?xNix(H2PO4)2 · 2H2O with M = Mg, Mn, Co, or Zn

New continuous substitutional solid solutions Mg_1−x Ni _x (H₂PO₄)₂ · 2H₂O, Mn_1−x Ni _x (H₂PO₄)₂ · 2H₂O, Co_1−x Ni _x (H₂PO₄)₂ · 2H₂O, and Zn_1−x Ni _x (H₂PO₄)₂ · 2H₂O (0 ≤ x ≤ 1.00) crystallizing in monoclinic space group P2₁/n have been synthesized. Their end-member is Ni(H₂PO₄)₂ · 2H₂O. Ni(H₂PO₄)₂ · 2H₂O is isostructural to magnesium, manganese, iron, cobalt, zinc, and cadmium dihydrogenphosphates. The chemical composition and the unit cell parameters have been determined for the solid solutions. Their IR spectra have been measured. Original Russian Text ? V.N. Viter, P.G. Nagornyi, 2007, published in Zhurnal Neorganicheskoi Khimii, 2007, Vol. 52, No. 1, pp. 19–25.     

Supramolecular pseudometallacycles in a nickel compound with 4,4-diaminodiphenylmethane: Synthesis and structure of {Ni[(CH2(C6H4NH2)2]2(NO3)2(H2O)2}

The [Ni(DDM)₂(NO₃)₂(H₂O)₂] complex (DDM is 4,4-diaminodiphenylmethane [CH₂(C₆H₄NH₂)₂]) is synthesized, and its structure is determined. The crystals are triclinic, space group P , a = 5.846(1) ?, b = 9.450(2) ?, c = 13.390(3) ?, α = 105.63(3)°, β = 98.13(3)°, γ = 105.84(3)°, V = 666.6(2) ?³, ρ_calcd = 1.553 g/cm³, Z = 2. The Ni(II) ion (in the inversion center) is bound to a distorted octahedral array formed by the nitrogen atoms of the primary amino groups of the DDM molecules and the oxygen atoms of the monodentate nitrato groups and water molecules (Ni(1)-N(3) 2.119(2) ?, Ni(1)-O(1) 2.122(2) ?, Ni(1)-O(w) 2.047(2) ?, angles at the Ni atoms vary in the 85.08(9)°–94.92(9)° interval). The structure contains supramolecular metallacycles formed by the O(w)-H…N(2) hydrogen bonds between the coordinated H₂O molecules and the terminal amino groups of DDM. The metallacycles are joined by the Ni²⁺ ions into infinite chains running in the [111] direction. Original Russian Text ? Yu.V. Kokunov, V.V. Kovalev, Yu.E. Gorbunova, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 11, pp. 1838–1843.     

Experimental evidence of structural transition from fcc to bulk bcc in nanophase metal clusters of (Fe)n, (Cr)n, (Mo)n and (W)n produced by CO2 laser multiphoton decomposition of metal carbonyls

We have produced nanophase metal clusters, (Fe)_n, (Cr)_n, (Mo)_n and (W)_n, by multiphoton decomposition of the corresponding metal carbonyls with a 10.6 μm CO₂ laser in the presence of Ar and SF₆. The size distribution was narrow and the average diameter was 6, 3.5, 2 and 1 nm for Fe, Cr, Mo and W clusters, respectively. The structure was found to be bcc for both Fe and Cr clusters, fcc for Mo clusters, and amorphous for W clusters (note that all the bulk metals have bcc structure). Considering the cluster sizes (9630, 1870, 230 and 30 for Fe, Cr, Mo and W clusters, respectively) estimated from their average diameters, it is likely that there exists a structural transition from fcc to bulk bcc with increasing cluster size in these metal clusters.     

Simulation of dielectric properties and stability of clusters (H2O)i, CO2(H2O)i, and CH4(H2O)i

Molecular dynamics method is used for studying complex permittivity ɛ and the stability of individual water clusters as a function of the number of involved molecules (7 ≤ i ≤ 20) and also the corresponding characteristics of water aggregates with a captured CO₂ or CH₄ molecule. Absorption of the latter molecules leads to considerable changes in dielectric properties and stability of clusters. In particular, upon the addition of a CO₂ molecule to a water cluster, the oscillation parameters of the real and imaginary parts of the permittivity change. Capture of a CH₄ molecule by a water aggregate changes the ɛ(ω) dependence from the relaxation to resonance type. For i ≥ 15, the thermal stability of individual water clusters can be lower than that of aggregates CO₂(H₂O) _i and CH₄(H₂O) _i . The mechanical stability of (H₂O) _{i ≥ 13} clusters can exceed that of heteroclusters under consideration. Clusters (H₂O) _i and CO₂(H₂O) _i have approximately the same dielectric stability, whereas aggregates CH₄(H₂O) _i exhibit lower stability with respect to electric perturbations. Original Russian Text ? A.E. Galashev, V.N. Chukanov, A.N. Novruzov, O.A. Novruzova, 2007, published in Elektrokhimiya, 2007, Vol. 43, No. 2, pp. 143–153.     

正极材料Li(Ni0.5Mn0.5)1-xMxO2 (M=Ti，Al；x=0，0.02)电化学行为的比较研究

0IntroductionMany efforts have been made to develop newmaterials as an alternative to LiCoO2due to the rela-tively high cost and toxicity of Co.Much attention hasbeen paid to layered structure cathode materials suchas LiMnO2and LiNiO2due to their lower co…     

Bi4-xEuxTi3-yMyO12（M=Fe，Co，Ni）纳米颗粒的制备及光学和磁学性能

三层结构的Aurivillius相的Bi_4-xEu_xTi_3-yM_yO₁₂（x=0~0.6;M=Fe/Co/Ni,y=0.01,0.02,0.04,0.06,0.08,0.10）纳米颗粒,是通过共沉淀法和后续的高温煅烧处理所制备的。利用XRD,SEM,PL,Raman,PPMS等方法对样品进行表征,研究了不同掺杂浓度下的产物的物相、形貌和性能等。实验结果表明,通过掺杂,发现纳米颗粒的粒径变小,形貌更均一,分散性也更好。通过对掺杂离子浓度的优化,发现Eu³⁺离子的掺杂浓度为x=0.4时,发光强度是最强的。此外,对Ti位进行了磁性离子（Fe³⁺,Co³⁺和Ni²⁺）的掺杂,实验结果发现随着掺杂的磁性离子浓度的减少,发光强度是逐渐增强,而且产物具有很好的铁磁性。     

NixCo3-xO4表面修饰对CdSe/TiO2纳米管阵列光电化学氧化水活性的影响

利用氨挥发诱导法在CdSe/TiO2纳米管阵列表面负载一层NixCo3-xO4。采用SEM、XRD、XPS、UV-Vis对样品进行表征,通过线性扫描伏安法测定光阳极的释氧电势来评价其光电水氧化活性。结果表明:表面NixCo3-xO4是尖晶石结构;相对于CdSe/TiO2纳米管阵列光阳极,NixCo3-xO4/CdSe/TiO2光阳极能将光电氧化水的过电势降低430 mV。Ni离子的引入使得NixCo3-xO4表面富含三价阳离子(Ni3+,Co3+),从而促进CdSe/TiO2光阳极光电水氧化的进行。     

室温下制备以{211}晶面为主的Ti1-xVxO2薄膜及其可见光催化性能

以金属Ti和V作为靶材,采用直流反应共溅射技术在室温下制备了以{211}晶面为主的锐钛矿相Ti_1-xV_xO₂薄膜,研究了不同V靶功率对Ti_1-xV_xO₂薄膜的薄膜成分、晶相结构和可见光催化性能的影响。研究表明,Ti_1-xV_xO₂薄膜的晶相结构为锐钛矿相,择优取向为(211),而结晶度受V靶功率的影响。随着V靶功率的增加,薄膜中V元素含量逐渐增加,同时,晶粒和沉积速率也逐渐增加。另外,当V靶功率为150 W时,薄膜的表面粗糙度值有一个最大值。V的掺杂导致薄膜的能带间隙变窄,对光的吸收向可见光区偏移,从而有效地改善了薄膜的可见光催化能力。当V靶功率为150 W时,Ti_1-xV_xO₂薄膜的能带间隙值为 2.82 eV,其在2 h的可见光照射下分解了80%的RhB染料。这被归结于能带间隙窄,高能晶面{211}和结晶度高的共同作用。