Pt/Ce0.8La0.2O1.9催化剂上巴豆醛选择性加氢

采用浸渍法制备了Ce0.8La0.2O1.9同溶体负载Pt催化剂,用于气相巴豆醛选择加氧反应中.采用X射线粉末衍射、程序升温还原、NH3程序升温脱附和拉曼光谱等技术对催化剂进行了表征.结果表明,随着Pt负载量增加,Pt/Ce0.8La0.2O1.9催化剂活性(TOF)和巴豆醇选择性均先增加后降低.当Pt负载量为3%时,...     

Pt-Au/CNT@TiO2作为甲醇燃料电池的高活性阳极催化剂

以TiO2包覆的多壁碳纳米管(CNT@TiO2)为载体,Pt和Au为活性物质,采用沉积紫外光催化还原法制备出高活性的甲醇阳极电催化剂Pt-Au/CNT@TiO2,并采用X射线衍射、透射电镜和X射线光电子能谱对催化剂样品的物化特征进行表征.催化剂的抗毒性能用循环伏安和交流阻抗测试来表征.结果表明,粒径为2～3nm的Pt-...     

前言

The 6th International Conference on Environmental Catalysis(6th ICEC)was held in Beijing from September 12 to September 15,2010.The ICEC is a series of con- ferences that was initiated in Pisa(1995)and followed up in Miami Beach(1998),Tokyo(2001),Heidelberg(2005) and Belfast     

A Novel Mononuclear Copper（Ⅱ） Complex：Crystal Structure and DNA Cleavage Ability

The reaction of N-tosylatirdine with 1,2-diaminopropane in dry benzene solution yields an intermediate H2L, N,N,N',N'-tetrakis(2-(p-tolylsulfonyl)aminoethyl) propane-1,2-diamine. The mononuclear copper(Ⅱ) complex, [CuLH2O]·H2O, was synthesized by the reaction between the intermediate and copper(Ⅱ) in absolute methanol. The complex has been characterized by IR, UV-vis and X-ray diffraction technology, and its crystal crystallizes in the orthorhombic system, space group Pbca with a = 15.589(1), b = 21.897(2), c = 27.645(2) , V = 9436.4(1) 3, Dc = 1.352 g/cm3, Z = 8, Mr = 960.68, F(000) = 4040, μ(MoKa) = 0.698 mm-1, S = 0.98, R = 0.0537 and wR = 0.1180 for 5804 observed reflections (I > 2σ(I)). In the crystal structure, a one-dimensional chain is formed by abundant hydrogen bond interactions. The interaction of the complex with DNA was monitored using agarose gel electrophoresis. The result shows that the complex can transform the supercoiled to nicked and liner forms, and has a concentration-dependent cleavage activity.     

用于NH3选择性催化还原NO的非钒基催化剂研究进展

NH3选择性催化还原NO (NH3-SCR)技术在燃煤电厂烟气脱硝过程中有着多年的工业应用经验,也是最有望实际应用于柴油车尾气NOx催化去除的技术之一.鉴于目前工业化应用的V2O5-WO3 (MoO3)/TiO2催化剂体系应用于柴油车尾气净化仍存在着诸多问题,开发新型、高效、稳定且环境友好的非钒基NH3-SCR催化剂体...     

介孔Al2O3负载PdO催化甲烷燃烧反应性能

采用浸渍法制备了介孔Al2O3(M-Al2O3)负载PdO催化剂,考察了其催化CH4燃烧反应性能.结果表明,以M-Al2O3为载体的PdO催化剂活性比普通Al2O3载体高得多,这很可能与M-Al2O3的孔道结构对PdO物种的限域作用有关.随着PdO/M-Al2O3催化剂焙烧温度的升高,甲烷催化燃烧活性先增加后降低,其中700oC焙烧的催化剂活性最高,400oC反应时CH4转化率为91%.此时Pd物种主要以PdO颗粒形式高度分散在载体的介孔孔道内,而高温焙烧时,Pd物种主要以Pd和PdO的混合晶相存在.尽管900oC焙烧制得的催化剂上CH4的转化率降低,但TOF值最大,这可能与该催化剂中同时存在金属Pd和PdO有关.     

Synthesis and Crystal Structure of（2E,6E）-2,6-bis（2,3-dimethoxybenzylidene）cyclohexanone

The new title compound (2E,6E)-2,6-bis(2,3-dimethoxybenzylidene)cyclohexanone (C 24 H 26 O 5,M r=394.45) has been synthesized,and its crystal structure was studied.The title compound crystallizes in the orthorhombic system,space group Pca2 1 with a=17.536(2),b=14.8515(16),c=8.0512(9),V=2096.8(4) 3,Z=4,D c=1.250 g/cm 3,λ=0.71073,μ=0.087 mm-1 and F(000)=840.The structure was solved by direct methods and refined to R=0.0533 and wR=0.1248 from 2727 observed reflections (I > 2σ(Ⅰ)).The title molecules are connected through hydrogen bonds to generate a 3-D supramolecule.The preliminary biological tests showed definitely biological activity for the title compound.     

A DFT Investigation on the Co-adsorption of H_2 and Ions inside the Carbon Nanotube

We studied the co-adsorption of hydrogen molecule and ions (Li,K,Mg,Ca) inside the single-walled carbon nanotubes (SWNTs) by using density-functional theory (DFT).The band structures (BS),density of states (DOS),charge transfer and difference charge density are presented.We discussed the interaction between the ions (Li,K,Mg,Ca) and H 2.Meanwhile,the binding energy indicates that ionization can increase the adsorption energy of H 2 in CNT.     

Synthesis of functional polyethylene <Emphasis Type="Italic">via</Emphasis> copolymerization of ethylene and substituted allene using bis(<Emphasis Type="Italic">β</Emphasis>-enaminoketonato)titanium catalysts

Novel copolymerization of ethylene with substituted allenes（CH₂=C = CH—R,1:R = n-butyl,2:R =n-octyl） using bis（β-enaminoketonato）titanium catalysts[PhN = C（R₂）CHC（R₁）O]₂TiCl₂（1a:R₁ = CF₃,R₂ = CH₃;1b:R₁ = Ph,R₂ = CF₃） has been investigated.In the presence of modified methylaluminoxane,these catalysts can copolymerize ethylene with substituted allenes,affording copolymers with unimodal molecular weight distributions and homogeneous compositions.By varying the reaction conditions,the comonomer incorporation can be tuned in the range of 0-3.6 mol%.¹H-NMR spectra reveal that the copolymerization proceeds through 1,2-insertion fashion of allene comonomer exclusively,and the regioselective nature maintains under various reaction conditions.The retained intra-chain double bond can be converted into the epoxy group under mild conditions.     

Rapid synthesis and consolidation of nanostructured Mg<Subscript>2</Subscript>SiO<Subscript>4</Subscript>–MgSiO<Subscript>3</Subscript> composites by high frequency induction heated sintering

Rapid synthesis and sintering of nanostructured MgSiO₃–Mg₂SiO₄ composites was investigated via a high-frequency induction heating sintering process. The advantage of this process is that it enables very quick densification to near theoretical density and prohibition of grain growth in nanostructured materials. High-density nanostructured MgSiO₃–Mg₂SiO₄ composites were produced by simultaneous application of 80 MPa pressure under an induced output power of 15 kW within 2 min. The grain sizes and hardness of MgSiO₃–Mg₂SiO₄ composites were investigated.