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1.
采用硝酸锌、五氧化二钒和氢氧化钠作为反应物,通过一个简单的CTAB辅助的水热方法制备了Zn3(OH)2V2O7·2H2O纳米片。运用XRD,ICP-AES,FTIR,HRTEM,EDS,FE-SEM对产物的晶相和形貌进行了表征。结果表明CTAB在控制产物的形貌、尺寸分布和自组装过程中起着关键作用。同时我们研究了产物的晶体生长行为和自组装过程。  相似文献   

2.
采用共沉淀法制备了Co3V2O8催化剂,并对催化剂进行了BET、XRD、H2-TPR、XPS、和 TEM等技术表征,研究了其丙烷氧化脱氢 (ODH) 制丙烯反应的催化性能。H2-TPR和XPS实验结果表明,Co3V2O8催化剂中晶格氧可以较容易转换成可动氧物种(即未完全还原氧物种),使催化剂内各种价态的钒之间易于进行氧化还原反应并形成氧缺位,催化剂的表面含有较多未充分还原氧物种O-和V4+ 物种。催化活性结果显示,在425℃和475℃,丙烯选择性分别为49.45%和33.74%,表现了较好的催化性能。  相似文献   

3.
Developing suitable anode materials for potassium-ion batteries (PIBs) remains a great challenge owing to the limited theoretical capacity of active materials and large radius of K+ion (1.38 ?). To solve these obstacles, by integrating the principles of multielectron transfer and rational porous crystal framework,we creatively propose the monoclinic Cu3(OH)2V2O7.2H2O (CVO) as a novel anode for PIBs. Furthermore,inspired by the met...  相似文献   

4.
采用溶剂热法,丁烷四羧酸(H4L)与水合乙酸钴经配位聚合反应合成了一个新型的双核Co(Ⅱ)聚合物[Co2L(MeOH)(H2O)4]n.nH2O(1),其结构经元素分析和单晶X-射线衍射表征。1属单斜晶系,C2/c空间群,晶胞参数a=2.802 6(3)nm,b=0.816 32(11)nm,c=1.630 1(2)nm,β=119.793(2)°,V=3.236 5(7)nm3,Z=8,Dc=1.925 Mg.cm-3,R1=0.097 5,wR2=0.223 1。1通过H4L桥联形成一维链,通过O-H┈O氢键作用形成了无限延伸的二维网络结构;在1中存在的分子内及分子间氢键使1具有三维网络结构。  相似文献   

5.
通过调变HAuCl4溶液的pH值和Au负载量,用沉积-沉淀法制备了一系列Au/Co3O4催化剂,并采用AES、BET、XRD、SEM、XPS和H2-TPR等技术对催化剂的结构和组成进行了表征,考察了制备条件对其在有氧气氛中催化N2O分解反应性能的影响规律,得到了催化剂最佳制备条件:HAuCl4溶液pH值为9,Au负载量为0.29%。催化测试结果表明:虽然ZnCo2O4的催化活性优于Co3O4,但0.31%Au/ZnCo2O4的活性和稳定性低于0.29%Au/Co3O4。500℃、在含氧气氛中连续反应10 h, 两者均可完全分解N2O,但在含氧、含水气氛中0.29%Au/Co3O4和0.31%Au/ZnCo2O4上的N2O转化率分别为92%和63%。究其原因,发现Au/Co3O4中Au和Co组分间存在协同效应,而Au/ZnCo2O4中Au和Co组分间则没有协同效应。  相似文献   

6.
采用废弃的鸡蛋壳作载体,沉积沉淀法制备了一系列不同Co3O4含量Co3O4/鸡蛋壳催化剂,并在连续流动微反装置上考察了N2O分解性能。结果表明,当Co3O4质量分数为20%时,催化剂表现出优异的N2O分解性能。在空速10000 h-1和N2O含量0.1%的条件下,400℃可实现N2O完全转化;其比活性约为Co3O4催化剂的4.3倍(反应温度为440℃);同时,该催化剂对原料气中3%O2、3.3%H2O和/或2.0×10-4 NO表现出较强的耐受性和较高的稳定性。分析催化剂的多种表征结果发现,CaCO3作为鸡蛋壳的主要成分,与活性组分Co3O4紧密结合,两者的强相互作用导致20%Co3O4...  相似文献   

7.
本文采用等体积浸渍法将活性组分Co3O4负载到具有大比表面积、独特三维交联介孔道的KIT-6分子筛上,制备一种负载型的Co3O4/KIT-6催化剂,并用于催化分解N2O反应.研究发现,负载Co3O4后的催化剂不仅保持了KIT-6有序的介孔结构,同时增大了催化剂的有效比表面积,提高了活性组分Co3O4的利用率,其催化活性基本与纯Co3O4相持平.通过对不同负载量的Co/KIT-6催化剂的活性测试发现,该催化剂的活性随着Co负载量的增加而提升.通过对30%Co/KIT-6催化剂的稳定性测试及其在杂质气体存在条件下的活性测试,表明30%Co/KIT-6催化剂具有较好的催化稳定性和杂质气体抗性,适用于实际工业生产尾气中的N2O处理.  相似文献   

8.
9.
Nb2O5·nH2O-PtRu/C的制备及其对甲醇氧化的催化作用   总被引:1,自引:0,他引:1  
李伟伟  张向军  卢世刚 《化学学报》2012,70(9):1073-1080
采用沉淀法制备了甲醇氧化电催化剂10%Nb2O5 nH2O-20%Pt10%Ru/C,并在Ar气氛下对它进行了热处理.用X射线衍射(XRD),透射电子显微镜(TEM)和X射线光电子谱(XPS)研究了热处理对催化剂的结构和形貌的影响,用循环伏安法和计时电流法研究了热处理对催化剂的电化学性能的影响.结果表明:催化剂中看不到Ru的衍射峰存在,Pt晶粒以面心立方体结构存在,Nb2O5 nH2O对Pt的结合能基本无影响;与20%Pt10%Ru/C相比,同温度热处理的条件下,10%Nb2O5 nH2O-20%Pt10%Ru/C催化剂中Pt,Ru合金化程度较差,活性组分颗粒较小、分散均匀,而且催化甲醇氧化性能和抗"CO"毒化性能较好,700℃热处理的10%Nb2O5 nH2O-20%Pt10%Ru/C的性能最好.Nb2O5 nH2O不仅能抑制热处理过程中活性颗粒的长大和Pt,Ru的合金化,还能促进氢离子的传递,提供活性"-OH",使甲醇及其氧化中间体更容易吸附-脱附.  相似文献   

10.
Remarkable efficiency of hydrogen peroxide utilization is reported for oxygenation of four organic sulfides catalyzed by a divacant lacunary silicotungstate, (Bu4N)4[γ-SiW10O34(H2O)2] (1), under mild conditions. The addition of imidazole, phosphate, or carboxylates significantly enhances the rate of organic sulfide oxygenation. Most notably, use of 1 and imidazole, both at 1% molar concentration, resulted in the quantitative conversion of phenylsulfide to sulfoxide with 1 equiv of H2O2 in 3 h, and to sulfone with 2 equiv of H2O2 in 6 h.  相似文献   

11.
Oxidative coupling of methane over Bi2O3–P2O5–K2O/Sm2O3 takes place giving more C2H4 as compared to C2H6. Sm2O3 supported Bi–P–K is a more active and selective catalyst, than TiO2, -Al2O3, SiO2 and MgO supported catalysts.
Bi2O3–P2O5–K2O/Sm2O3 , . Bi–P–K, Sm2O3, , TiO2, -Al2O3, SiO2, MgO.
  相似文献   

12.
纳米Co3O4具有尖晶石结构,Co3 占据八面体位,具有较高的晶体场稳定化能,在空气中低于800℃时十分稳定,是优良的催化材料[1]。Co3O4还可以作为高比能锂离子电池负极材料具有非常好的电化学活性,充放电容量高达960m A h·g-1。纳米Co3O4在紫外、可见及近红外区域都有良好的吸收效果,因此,在隐身技术、保温节能技术等领域具有潜在的应用前景。所以,Co3O4超细粉体的制备和应用研究具有十分重要的意义。我们合成了草酸盐先驱物制备纳米Co3O4用作隐身材料,因此对先驱物的热分解过程研究是十分必要的。热分析方法在了解先驱物热分解反应的物理…  相似文献   

13.
Two new arsenic–vanadium clusters, [Co(2,2- bpy)3]2[As8V14O42(H2O)] · 3H2O (1), [2,2-bpy][Ni(2,2-bpy)3]2[As8V14O42(H2O)] · 3H2O (2) (2,2-bpy=2,2-bipyridine), have been hydrothermally synthesized and characterized by IR, elemental analysis, UV–VIS, EPR, TGA, XPS, and single crystal X-ray diffraction analysis. Crystal data: 1, triclinic, P1, a=14.368(3) Å, b=16.753(3) Å, c=24.632(5) Å, =94.15(3)°, =93.16(3)°, =113.05(3)°, Z=2; 2, monoclinic, P21/c, a= 30.2150(4) Å, b=14.0690(3) Å, c=26.0536(3) Å, =106.8960(10)°, Z=4. X-ray crystallographic studies showed that crystals 1 and 2 are both composed of discrete cluster anion [As8V14O42(H2O)]4– and transition metal coordination complexes [M(2,2-bpy)3]2+ (M=Co or Ni). Interestingly, compound 2 contains another neutral organic space filler of 2,2-bpy. To the best of our knowledge, compounds 1 and 2 are the first examples of structurally characterized vanadium/2,2-bpy/arsenate polyoxometallates.  相似文献   

14.
以十六烷基三甲基溴化胺(CTAB)为模板剂,通过调变CTAB浓度水热合成了氧化钴前驱体,焙烧制得棒状形貌的Co3O4,在其表面浸渍K2CO3溶液制得K改性的Co3O4催化剂,用于N2O分解。用X射线衍射(XRD)、N2物理吸附(BET)、扫描电镜(SEM)、X射线光电子能谱(XPS)、H2程序升温还原(H2-TPR)和O2程序升温脱附(O2-TPD)等技术对催化剂进行了表征,考察了CTAB/钴及尿素/钴物质的量比等制备参数对Co3O4催化分解N2O活性的影响。结果表明,CTAB浓度为0.05 mol/L、CTAB/钴离子物质的量比为1、尿素/钴离子物质的量比为4时,所制备的Co3O4催化剂具有较高的N2O分解活性,而K改性可以进一步提升其催化性能。K改性的Co3O4在有氧有水气氛中400℃下进行N2O分解反应,50 h后N2O转化率仍保持在91%以上。  相似文献   

15.
Three novel 1:2 composite compounds prepared with the isopolyanions and lanthanide-organic units, (NH4)2{[Ln2(HL)2(H2O)9][(H2W12O40)]}·nH2O (Ln = Gd3+ (1), Tb3+ (2), n = 15; Ho3+ (3), n = 10; L = pyridine-3,5-dicarboxylate) were synthesized at room temperature and characterized by routine methods. X-ray structural analysis reveals that these structures are isomorphic: two crystallographically independent Ln3+ ions (Ln1 and Ln2) locate in different coordination environments; two ligands plays dissimilar coordination mode; the isopolyanion cluster acts as a tridentate ligand and connects three Ln3+ ions (Ln1, Ln1′ and Ln2) forming an unusual 2D undee-layer. The room temperature luminescent of 2 has been studied and exhibits a Tb3+ characteristic emission in the range of 450–650 nm.  相似文献   

16.
Acid nickel oxovanadate, [Ni(H2O)6]2[H2V10O28] · 6H2O (I) was synthesized and studied by X-ray diffraction analysis, thermogravimetry, powder X-ray diffraction, and IR spectroscopy. The crystals are triclinic: space group , a = 8.869(2) ?, b = 10.869(2) ?, c = 11.116(2) ?, α = 65.14(3)°, β = 74.11(3)°, γ = 70.47(3)°, V = 907.41 ?3, ρ(calcd.) = 2.56 g/cm3, Z = 1. Original Russian Text ? G.Z. Kaziev, A.V. Oreshkina, S.H. Quinones, D.A. Alekseev, V.E. Zavodnik, T.Yu. Glazunova, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 8, pp. 593–598.  相似文献   

17.
在水乙醇混合溶剂中,首次得到了2-羰基丙酸水杨酰腙、1,10-菲啰啉与硝酸钆形成的配合物[Gd(C10H9N2O4)(C10H8N2O4)(H2O)3]2·phen·4H2O,并测试了其单晶结构。该配合物属三斜晶系,空间群为P-1。每个配合物分子中有两个九配位的钆的结构单元,每个钆离子与两个三齿配体2-羰基丙酸水杨酰腙(分别以负一价和负二价形式)和三个水分子配位。每个钆单元在空间呈扭曲的单帽四方反棱柱。同时还有一个游离的1,10-菲啰啉存在于晶格中,通过氢键与配位水作用。生物活性试验表明该配合物对三种病原菌有一定的抑菌活性。  相似文献   

18.
A novel binuclear praseodymium(III) complex with N-(2-propionyl)salicyloylhydrazone (C10H10N2O4, H3L) and p-hydroxybenzoic acid (C7H6O3, Phba) was prepared in a H2O-C2H5OH mixed solution, and the crystal structure of [Pr2(H2L)2(Phba)4(H2O)2] · 2H2O (I) was determined by X-ray single crystal diffractometry. Complex I crystallizes in the monoclinic system, space group P21/c, a = 1.1050(4), b = 1.9534(7), c = 1.2376(4) ?, β = 94.955(7)°, and Z = 4. In the structure each Pr3+ ion lies in a single capped square antiprism geometry coordinated by carboxyl O and acyl O atoms and azomethine N atom of one ligand (H2L form), which coordinates via the keto form, four carboxyl O atoms from two Phba, and O atoms of two water molecules. In each molecule, two tridentate ligands were coordinated by the H2L form, and each Pr3+ ion was chelated by the carboxyl group from Phba. The carboxyl groups of H2L and other two Phba were coordinated via μ2-bridging form and bidentate bridging form, respectively. Complex I and ligands Phba and H3L were also searched for biological activity against Valsa mali by the growth rate method. The result showed that the inhibitory rate of ligands Phba and H3L is better than complex I, especially Phba.  相似文献   

19.
By the reaction of [Mo3S4(C2O4)3(H2O)3]2− with PdCl2 and NH4H2PO2 as a reducing agent, followed by the addition of PPh3, a new oxalate cuboidal cluster complex [Mo3(PdPPh3)S4(C2O4)3(H2O)3]2− is obtained. It was isolated and structurally characterized as K2[Mo3(PdPPh3)S4(C2O4)3(H2O)3]·0.5H2O. Original Russian Text Copyright ? 2008 by A. L. Gushchin, M. N. Sokolov, D. Yu. Naumov, and V. P. Fedin __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 4, pp. 775–778, May–June, 2008.  相似文献   

20.
用水热法和共沉淀法分别制备了Nd-Co3O4催化剂,催化分解N2O。其中,水热法制备的Nd-Co3O4催化活性较高。在不同组成的Nd-Co3O4中,优化出了较高活性的0.01Nd-Co3O4催化剂,在其表面浸渍K2CO3溶液制备K改性催化剂(K/Nd-Co3O4)。用X射线衍射(XRD)、N2物理吸附、扫描电镜(SEM)、X射线光电子谱(XPS)、程序升温还原(H2-TPR)、O2程序升温脱附(O2-TPD)等技术表征催化剂结构。结果表明,Nd-Co3O4和K改性催化剂均为尖晶石结构;K改性弱化了催化剂表面Co-O键,有利于表面氧的脱除,提高了催化剂活性。有氧有水气氛350 ℃连续反应40 h,K/Nd-Co3O4催化剂上的N2O分解率超过90%,稳定性较好。  相似文献   

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