In对Ni/SiO2催化剂苯甲醚加氢脱氧性能的影响:苯环加氢及 C-C键氢解的抑制作用

由可再生木质素基生物质油加氢脱氧制三苯(苯、甲苯及二甲苯)及燃油可减少对化石能源依赖、缓解环境问题,加氢脱氧催化剂的研究开发为众多学者密切关注.我们以低成本金属Ni为加氢脱氧活性组分,采用金属In对金属Ni催化剂进行改性,旨在增加以苯甲醚为模型反应物加氢脱氧中的三苯收率、降低金属Ni的C-C键氢解及甲烷化活性,提高反应过程中碳收率、降低耗氢量.采用等体积浸渍-程序升温还原法制备了Ni/SiO2及Ni-In/SiO2催化剂,研究了Ni/In比及Ni含量对In改性Ni/SiO2催化剂结构和苯甲醚加氢脱氧性能的影响,利用H2-TPR,H2化学吸附,XRD,NH3-TPD,XPS,TEM及N2物理吸附-脱附等手段对催化剂及其前驱体进行了表征,采用石英管固定床反应器在300°C、常压、H2/苯甲醚摩尔比25及苯甲醚重时空速0.4 h-1的反应条件下考察了催化剂苯甲醚加氢脱氧性能,分析了催化剂结构与性能之间的关系.H2-TPR结果显示,金属In的加入抑制了催化剂前驱体中Ni物种的还原.XRD,H2化学吸附,HAADF-STEM-EDS及XPS等结果表明,经450°C还原制备的Ni-In/SiO2双金属催化剂中Ni和In接触紧密.In的加入明显降低了催化剂表面金属Ni的活性位数量;并且,Ni/In比越低Ni-In/SiO2催化剂H2化学吸附量越小.XPS结果还显示,Ni-In/SiO2催化剂中存在金属In向Ni转移电子.上述结果说明,在Ni-In/SiO2催化剂中金属Ni与In存在较强的相互作用.在苯甲醚加氢脱氧反应中,与Ni/SiO2催化剂相比,Ni-In/SiO2催化剂虽因表面Ni密度较低而具有较低苯甲醚转化率,但其苯环加氢、C-C键氢解及CO甲烷化活性较低,因而具有较高的三苯及环己烷选择性;并且,随Ni/In比的降低(即In含量的增加),Ni-In/SiO2催化剂的加氢、氢解及甲烷化能力呈减弱趋势.随Ni质量含量提高,Ni-In/SiO2双金属催化剂上苯甲醚转化率提高,但对三苯选择性及C-C键氢解能力影响不明显.经分析认为,与Ni/SiO2相比,Ni-In/SiO2催化剂较低的苯加氢及C-C键氢解活性与In对表面连续Ni位隔离作用及金属镍位电子云密度提高有关.在优化的反应条件下,Ni质量含量为40%、Ni/In比为40的Ni-In/SiO2催化剂上三苯收率为60.4%,高于相同Ni质量含量Ni/SiO2催化剂上三苯收率(51.6%).     

Electron Transfer. 130. Reductions with Indium(I)(1)

Aqueous solutions of the hypovalent state indium(I) have been prepared by treatment of In(Hg) with silver triflate in acetonitrile, followed by dilution with oxygen-free water. These solutions are stable for over 5 h at 25 degrees C. In(I)(aq) reacts with oxidants of the type [(NH(3))(5)Co(III)(Lig)](2+) (In(I) + 2Co(III) --> In(III) + 2Co(II)), and kinetic profiles are consistent with a two-step sequence proceeding with formation of the metastable state In(II), which reacts rapidly with Co(III). Rate ratios for reductions of halogeno-substituted oxidants point to predominance of halide-bridged paths for the chloro, bromo and iodo complexes. Reductions of carboxylato-substituted derivatives are slow but appear to entail inner-sphere precursors if aided by an O-donor group in a position favorable for chelation. In no case is there evidence for reaction via initial reduction of the ligand (the radical-cation mechanism) although the potential of the In(I,II) couple (-0.40 V) allows this path for carbonyl-substituted oxidants. Reductions by In(I), like those by Eu(II), make no significant use of bridging by heterocyclic donor nitrogen centers in pyridine and pyrazine complexes.     

S/In_2O_3纳米材料的制备及其在锂硫电池正极材料中的应用

以硝酸铟和蔗糖为原料,依次经水热反应和550℃碳化制得In_2O_3纳米材料(nano-In_2O_3);将硫渗入nanoIn_2O_3得S/In_2O_3,其结构和微观形貌经SEM,TEM和XRD表征。将S/In_2O_3,导电炭黑和聚偏氟乙烯按质量比8∶1∶1制成正极材料(1);将1涂覆于铝箔上,锂片作参比电极,1 mol·L~(-1)LiPF_6的DMF/DOL(V/V=1/1)溶液为电解液,组装成锂硫半电池。采用循环伏安法和恒电流充放电法研究了S/In_2O_3的电化学性能。结果表明:在1.95 V和2.3 V处有两个还原峰,2.5 V处有一个氧化峰。电流密度为335 m A·g~(-1),首次放电比容量为1 357m Ah·g~(-1),库伦效率为82.75%。经80次充放电后,放电比容量为537 m Ah·g~(-1)。     

Growth of self-organized hierarchical ZnO nanoarchitectures by a simple In/In2S3 controlled thermal evaporation process

Novel hierarchical ZnO nanoarchitectures, such as microtrepangs, microbelts, nanoflowers, nanocombs, nanowheels, and nanofans assembled by ZnO nanocones, nanobowling pins, nanobottles, nanoarrows, and nanonails, have had their growth controlled by the thermal evaporation of Zn and a mixture of In and In2S3. Both the morphologies of the products and their construction units could be efficiently controlled by simple adjustment of the weight ratio of In/In2S3. The phase structure, morphologies, and photoluminescence properties of the ZnO products were investigated by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and photoluminescence spectroscopy. These novel hierarchical ZnO nanoarchitectures may be attractive building blocks for creating optical or other nanodevices.     

Novel corrugated In9 anionic layer in Li2Y5In9: square pyramidal In5 clusters interconnected by unusual butterfly In4 clusters

The new ternary polar intermetallic phase, Li2Y5In9, was obtained by high-temperature solid-state reactions of the corresponding elements inwelded Ta tubes. Its crystal structure was established by a single-crystal X-ray diffraction study. Li2Y5In9 crystallizes in the tetragonal space group P4/nmm (No. 129) with cell parameters of a = b = 10.1242(4), c = 15.1091(10) A and Z = 4. The structure of Li2Y5In9 features a two-dimensional corrugated anionic In9 layer composed of two types of square pyramidal In5 units and butterfly In4 units. There are two types of square pyramidal In5 units: one with normal In-In bonds and another one with greatly elongated In-In separations within its In4 square. Packing of these 2D In9 layers resulted in cavities and tunnels that are occupied by Y and Li atoms. Extended-Hückel tight-binding calculations indicate that Li2Y5In9 is metallic.     

Stabilization by a divalent transition metal in lead indium quaternary selenide, Fe(0.47)Pb(8.04)In(17.37)Se(34), and specific indium coordination

Single crystals of the first M-Pb-In-Se quaternary selenide, Fe(0.47)Pb(8.04)In(17.37)Se34, with the structure stabilized by a divalent transition metal (M = Fe), have been grown by a solid-state reaction. The Fe(II) ions partially occupy at the In sites with various Fe/In ratios. Thus, a new crystal structure is evolved by partially occupied minor Fe atoms at In sites. A part of the In atoms shows remarkably distorted octahedral coordination. This compound shows relatively high conductivity (approximately 40 S/m at 300 K) with a narrow-band-gap-type semiconducting property (Ea = 0.078 eV).     

Phase stabilization through electronic tuning: electron-poorer alkali-metal-indium compounds with unprecedented In/Li clusters

Three alkali-metal-indium compounds K34In(92.30)Li(12.70) (I), K14Na20In(91.82)Li(13.18) (II), and K14Na20In(96.30) (III) (all Rm) have been synthesized and characterized by structural and physical property measurements and electronic structure calculations. Novel mixed In/Li anionic icosahedra and fused icosahedra form in I and II. All three contain In28 as the first triply fused In icosahedra, which are further linked into (In28)In(In28) sandwich adducts in compounds I and II and (In28)In2(In28) in III. Stabilization of these electron-poorer phases through electronic tuning occurs via two different structural (redox) perturbations, either by substitution of certain indium atoms in the clusters by electron-poorer lithium atoms or by the introduction of defects and disorder in the fused cluster (III). The preferential occurrence of either substitutions or defect formation in the clusters is consistent with extended Huckel band calculation results for both the ideal pure indium phase and the Li-substituted equivalent. Model (ideal) and experimental EF values (based on stoichiometries) fall around a pseudogap in DOS. All three compounds are metallic according to both EHTB band calculations and measured resistivities. The cations (A = K, Na) in all the three structures generate A136 clathrate-IotaIotatype networks with remarkably specific and transferable cation dispositions around the two types of anionic cluster units.     

Das Verhalten der Alkalimetalle zu den Metallen der Gruppe III B

The following binary systems have been investigated by thermal analysis: Li/Ga, Rb/Ga, Cs/Ga, Li/In, Na/In, K/In, Rb/In, Cs/In, K/Tl, Rb/Tl, Cs/Tl. The intermetallic compounds found by thermal analysis have been confirmed by measurements of the atomic volumes. Furthermore use was made of X—ray powder diagrams; These showed too many reflexes so that an evaluation was not possible. The compounds are listed in “Inhaltsübersicht”. The underlined phases are melting congruently; the other ones are formed by peritectic reactions; as usual the composition of these compounds is not certain. Finally a survey is given of the systems of the alkaline metals with Al and the elements of the IIIB group.     

Stabilisierung von M+‐Ionen (M = In,Tl) durch Dibenzyldichlorogallat

Stabilization of M⁺ Ions (M = In, Tl) by Dibenzyldichlorogallate MCl reacts with (PhCH₂)₂GaCl to give M[(PhCH₂)₂GaCl₂] [M = In ( 1 ), Tl ( 2 )]. 1 and 2 were characterized by NMR, IR and MS techniques. In addition, an X‐ray structure determination of 1 was performed. According to this, 1 consists of four‐membered In₂Cl₂ rings connected by weak In…Cl contacts (344 pm) along [010] to a coordination polymer. The In⁺ ion is coordinated by four In–Cl and two In‐aryl interactions.     

Electronic structures of KNa3In9 and Na2In, two metallic phases with classical closed-shell electronic configurations

The cluster compounds KNa3In9 [K2Na6(In12)(In)6] and Na2In [(Na)8(In4)], which contain In12 icosahedra interbridged by 4-bonded In atoms and isolated In4 tetrahedra, respectively, both have classical closed-shell electronic configurations but show metallic transport properties. These contrasts have been studied by means of first-principles density functional methods (LMTO-ASA). Several bands cross the Fermi level in both compounds, consistent with their metallic properties. In KNa3In9, the metal atom framework alone is sufficient to generate a metallic characteristic. The alkali-metal s and indium p orbitals mix considerably in both phases, providing for substantial covalent contributions to their stabilities as well as bands crossing Ef. The participation of Na atoms in the 3D bonding networks is more striking in cation-richer Na2In than in KNa3In9.     

Indacyclopentadienes and Aromatic Indacyclopentadienyl Dianions: Synthesis and Characterization

A series of unprecedented metallacycles of indium, including indacyclopentadienes ( 2 ), spiro indacyclopentadienes ( 3 ), aromatic indacyclopentadienyl dianions with an In−Li bond ( 4 ), and aromatic indacyclopentadienyl dianions with an In−In bond ( 5 ), were synthesized and structurally characterized by single-crystal X-ray structural analysis for the first time. Both indacyclopentadienes 2 and 3 were synthesized by reaction of 1,4-dilithio-1,3-butadienes with InCl₃. Structural transformations between 2 and 3 were observed. Reduction of indacyclopentadienes 2 with an excess amount of lithium afforded aromatic indacyclopentadienyl dianions 4 with an In−Li bond or 5 with an In−In bond, respectively, depending on the substituents on the ring. The aromatic character of 4 and 5 was confirmed by both experimental measurements and theoretical analysis.     

Structure and bonding of Sr3In11: how size and electronic effects determine structural stability of polar intermetallic compounds

The binary compound Sr(3)In(11) (SrIn(3.667)) was synthesized and structurally characterized by X-ray diffraction experiments. It crystallizes in the orthorhombic La(3)Al(11) structure type (space group Immm, Z = 2; a = 4.9257(6), b = 14.247(2), c = 11.212(2) A). The crystal structure of Sr(3)In(11) bears features of the monoclinic EuIn(4) structure, which is adopted by SrIn(4), and the prominent tetragonal BaAl(4) structure. Sr(3)In(11) is stable until 550 degrees C. At higher temperatures it decomposes peritectically into SrIn(2) and In. Structural stability and bonding properties of Sr(3)In(11) were investigated by first principles calculations and compared to SrIn(4) in the monoclinic EuIn(4) and the tetragonal BaAl(4) structure. All three structures consist of a three-dimensional, polyanionic, network formed by In atoms and Sr cations encapsulated in cages. For the BaAl(4)-type SrIn(4), In-In network bonding is perfectly optimized. In contrast, the networks of EuIn(4)-type SrIn(4) and Sr(3)In(11) appear hypo- and hyperelectronic, respectively. The formation of Sr(3)In(11) with a composition close to 1:4 and the nonexistence of BaAl(4)-type SrIn(4) is explained by a delicate interplay of size and electronic factors governing structural stability in the In-rich part of the Sr-In system.     

Electronic stabilization effects: three new K-In-T (T = Mg, Au, Zn) network compounds

The ternary compounds K(34)In(91.05(9))Mg(13.95(9)) (I), K(34)In(96.19(6))Au(8.81(6)) (II), and K(34)In(89.95(1))Zn(13.05(7)) (III) have been synthesized by high-temperature means and structurally characterized by single-crystal X-ray diffraction methods. All are analogues of earlier products in which Li is substituted for some In in a hypothetical K(34)In(105) lattice. They consist of complex three-dimensional anionic networks built of In(12) icosahedra and M(28) triply fused icosahedra (M = In or In/T and T = Mg, Au, or Zn). The K atoms bridge between cluster faces or edges and form K(136) clathrate-IotaIota type networks. Two neighboring M(28) units are interconnected by an M atom to form a sandwich complex (M(28))M(M(28)) in I and II or by a Zn-Zn dimer in (M(28))ZnZn(M(28)) in III. Mixed In/T sites only occur in the M(28) portions. Phase stabilization through electronic tuning is present in all three via substitution of the electron-poorer T elements for In. Extended Hückel analyses indicate that all metal-metal bonding within the M(28) cluster appears to be optimized in I and III even though both are metallic. The size of the substituted element is also important in the structural features, as is especially shown by the Zn compound.     

AeMg(5)In(3) (Ae = Ba, Sr): new intermetallic compounds with well-differentiated roles for the normal cation types

The isostructural phases BaMg4.787(3)In3.213 and SrMg4.837(2)In3.163 were synthesized via high-temperature reactions of the elements in welded Ta tubes. The orthorhombic crystal structure established for these by single-crystal X-ray diffraction means (space group Pnma, Z = 4) features a 3D Mg-In network formed from condensed 21-vertex polyhedra that are centered by Ba (Sr), viz., Ae@Mg5M7In9 (M = Mg/In). Three of eight independent network sites are co-occupied by >90% Mg and <10% In(M). The network structure is the inverse of that found in the isopointal Ca(CaIn4)Au3, as clearly delineated by site charge estimates for the equivalent In3 versus Au3 positions. Tight-binding LMTO and extended Hückel calculations on the ordered AeMg5In3 support the differentiation of Mg and Ae in the structure, with substantial participation of Mg in dominant Mg-In bonding, but mainly an electron donor role for Ae. The Fermi energies lie close to pseudo gaps but with substantial DOS remaining, consistent with their measured metallic properties. An unmixed ideal AeMg5In3 would be isostructural with YCo5P3, with comparable polyhedra, but the small P in the latter lacks an effective interbridging role.     

空心球形In2O3/ZrO2-TiO2纳米复合材料多模式光催化

本文以聚苯乙烯(PS)胶球为模板,通过一步水浴法结合煅烧后处理制备了不同比例的In_2O_3/ZrO_2-TiO_2空心球状复合材料(简写为In_2O_3/ZrO_2-TiO_2-H)。通过X-射线衍射、扫描电镜、X-射线光电子能谱、紫外-可见漫反射吸收光谱和氮气吸附-脱附等测试手段对该系列复合材料的结构、组成和形貌进行了表征。结果表明,In_2O_3/ZrO_2-TiO_2复合材料经PS模板处理后呈现空心球状结构,球壁由纳米粒子堆积而成。将In_2O_3与ZrO_2-TiO_2复合后其光吸收性能呈现了一定的红移现象,且In_2O_3/ZrO_2-TiO_2-H(1∶4)的比表面积较大(66.92m~2·g~(-1))。同时,为了考察该复合材料的光催化性能,在多模式光催化条件下对甲基橙的降解情况进行了研究。结果表明,In_2O_3/ZrO_2-TiO_2-H(1∶4)表现出较好的光催化性能,其光催化活性高于P25、ZrO_2、In_2O_3/ZrO_2-TiO_2及其他体积比的In_2O_3/ZrO_2-TiO_2-H。     

Préparation et Étude Physico-chimique de Quelques Copolyamides Aromatiques Séquencés. II. Preuves de I'Existence de Séquencés dans les Copolycondensats

In order to prove a block structure, copolyamides synthetized by a two-stage low-temperature solution polycondensation process were extracted by suitable solvents. The fractions obtained were characterized by various physicochemical techniques. In particular, the presence of insoluble segments in the fractions containing soluble homopolyamide was revealed by means of thermogravimetry and infrared     

High performance solution-processed indium oxide thin-film transistors

In2O3 thin-film transistors (TFTs) were fabricated on various dielectrics [SiO2, self-assembled nanodielectrics (SANDs)] by spin-coating In2O3 film precursor solutions consisting of ethanolamine (EAA) and InCl3 in methoxyethanol. Optimized film microstructures are characterized by the high-mobility In2O3 00 L orientation and are obtained only within a well-defined range of base: In3+ molar ratios. Electron mobilities as high as approximately 44 cm2 V(-1) s(-1) are measured for n+-Si/SAND/In2O3/Au devices using an EAA/In3+ molar ratio = 10. This result combined with Ion/Ioff ratios of approximately 10(6) and <5 V operating voltages is encouraging for high-speed applications.In2O3 thin-film transistors (TFTs) were fabricated on various dielectrics [SiO2, self-assembled nanodielectrics (SANDs)] by spin-coating In2O3 film precursor solutions consisting of ethanolamine (EAA) and InCl3 in methoxyethanol. Optimized film microstructures are characterized by the high-mobility In2O3 00 L orientation and are obtained only within a well-defined range of base: In3+ molar ratios. Electron mobilities as high as ~44 cm2 V(-1) s(-1) are measured for n+-Si/SAND/In2O3/Au devices using an EAA/In3+ molar ratio = 10. This result combined with Ion/Ioff ratios of approximately 10(6) and <5 V operating voltages is encouraging for high-speed applications.     

Synthesis and characterization of the new cluster phase K39In80. Three K-In compounds with remarkably specific and transferable cation dispositions

The titled compound K(39)In(80) (Pearson symbol hP238) has been synthesized by fusion of the elements in stoichiometric proportions in Nb containers. The trigonal structure was established by single-crystal X-ray means (P3macrom1, Z = 2, a = b =17.211(2) A, c = 28.888(6) A). The crystal structure can be described as a three-dimensional indium network composed of five kinds of clusters: three types of empty In(12) icosahedra with different exo-bonding and symmetry, A (12 exo-bonds, 3macrom), B (12 exo-bonds, m), and C (6 exo-bonds, 3macrom); an In(16) icosioctahedron centered by a tetrahedral In atom (D, 3m); and a rather open In(15) spacer (E, 3m). This new intermediate lies between K(17)In(41) and K(22)In(39). Remarkably specific and transferable potassium dispositions about each cluster anion occur in the title compound as well as in K(17)In(41) and K(22)In(39). This characteristic makes it easier to understand the structural relationships among these three compounds, which all exhibit a common K(136) clathrate-II network of alkali metal atoms that are stuffed by cluster anions. The presence of the regular cation positions is probably decisive for the formation of all three structures. The title compound is metallic.     

Kinetics and stoichiometry in the Karl Fischer solution

The mechanisms of the Karl Fischer (K.F.) reaction are reviewed and further investigated. Both kinetic measurements of the iodine concentration and chromatographic determinations of the reaction products were performed. In alcoholic solutions mainly alkyl sulfite is oxidized, and a reaction via partial formation of sulfur trioxide is proposed. In methanol an exact 1:1 stoichiometry (H2O:I2) has been verified. In the aprotic, dipolar solvents acetonitrile, DMF and propylene carbonate HSO3- is oxidized by iodine. Based on formation and subsequent hydrolysis of base - SO3 adducts the stoichiometric factor for water is determined by type and concentration of the base, by the concentration of water and by the solvent itself. - In K.F. reagents the oxidation of SO2 by aerial oxygen to sulfate and alkyl sulfate takes place as a side reaction.     

Reaction of 5-alkylidenerhodanines with diazonium salts

In the action of diazonium salts on 5-alkylidenerhodanines, azo compounds are formed by the replacement of one or two hydrogen atoms in the methyl group. In the case of 5-ethylidenerhodanines, the formation of an azorhodanine through the replacement of the alkylidene residue by an arylazo group takes place simultaneously. In the formazyl derivatives the long-wave absorption maximum is displaced hypsochromically by 15–20 nm as compared with the dyes having a single azo group.