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1.
采用水浴液中阴离子直接交换法合成了具有不同钒含量的Keggin结构磷钨钒杂多阴离子PW(12-n)VnO(40)(n=1—5)柱撑水滑石,用元素分析、XRD和IR对柱撑产物的组成和结构进行了表征.XRD结果给出柱撑产物的底面间距达1.47M.DTA结果表明柱撑产物的热稳定性高于水滑石前驱体,且与杂多阴离子中V含量相关.由不同温度下焙烧样品的XRD和IR研究可知,柱撑产物的热分解过程为:<250℃时脱除物理吸附水和层间水;250~400℃范围内脱羟基(同时伴随着层间Keggin离子结构的破坏);400℃以上生成WO3和Mg2V2O7,后者在750℃以上分解为MgO和V2O5.  相似文献   

2.
新型层柱材料ZnAl-XW_(11)Co的合成、表征及催化活性胡长文,刘彦勇,王作屏,张继余,王恩波(东北师范大学化学系,长春130024)关键词层柱化合物,杂多阴离子,Keggin结构,乙酸,正了醇,酯化化学组成通式为的阴离子粘土具有独特的层柱结构?..  相似文献   

3.
新型层柱催化剂Zn2Al-XW11Z的催化氧化活性及热稳定性   总被引:4,自引:0,他引:4  
新型层柱催化剂Zn2Al┐XW11Z的催化氧化活性及热稳定性*贺庆林胡长文**张云峰王恩波(东北师范大学化学系,长春130024)关键词层柱催化剂,杂多阴离子,氧化活性,热稳定性,苯甲醛,氧化同多和杂多阴离子柱撑水滑石是近年来新开发的层柱状催化材料,...  相似文献   

4.
杂多阴离子柱撑水滑石层柱相互作用(Ⅰ)李兴林*佘益民郭军蒋大振(中国科学院长春应用化学研究所长春130022)(吉林大学化学系长春)关键词杂多阴离子,柱撑水滑石,XPS,IR,XRD1996-06-18收稿,1996-10-12修回国家自然科学基金资...  相似文献   

5.
新型层柱催化剂ZnAl-XW(11)Z的酯化催化活性   总被引:8,自引:0,他引:8  
用离子交换法制备了层柱催化剂ZnAl-XW11Z(X=P,Ge,B和Co:Z=V,Ti,Cr和Co等);XRD和IR测试结果表明,该化合物具有通道高度为0.99±0.01nm的层柱的结构,层间阴离子保持Keggin结构骨架;对乙酸与正丁醇的催化反应,它比HY分子筛具有更高的催化剂活性;吸附吡啶的IR测定结果表明,它同时具有有B酸和L酸两种酸性中心。  相似文献   

6.
高比表面TiO_2柱层状HLaNb_2O_7的制备和表征   总被引:2,自引:0,他引:2  
郭宪吉  侯文华  陆春良  颜其洁 《化学学报》2003,61(12):1976-1979
采用分步离子交换法,将含钛多聚阳离子嵌入层状镧铌酸(HLaNb_2O_7)的层 间,通过焙烧,制得了TiO_2柱层状镧铌酸(TiO_2-HLaNb_2O_7)。应用XRD, FTIR,TEM和BET(Brunauer-Emmett-Teller)等技术对该材料进行了表征。结果表 明,TiO_2-HLaNb_2O_7具有较大的层间距(1.61 nm,450 ℃)和较高的比表面积 (S_(BET) = 132 m~2·g~(-1)),而且是一中孔材料,其孔径分布曲线上呈现一 狭窄的孔分布,最可几孔直径为3.3 nm。  相似文献   

7.
层柱人工水热合成皂石的制备与表征(英)   总被引:5,自引:0,他引:5  
利用具有理想皂石结构的人工水热合成蒙皂石为层原料,通过与羟基聚合铝离子([Al13O4(OH)24(H2O)12]7+)交换反应合成得到了一种层柱粘土。实验对于该铝柱皂石进行了粉末XRD,FT-IR和TG-DTA表征。氮气吸附实验说明其高温活化(773K,2 h)产物具有很高的BET比表面(360 m2·g-1)。相对于层柱蒙脱土,层柱皂石显示了更高的催化裂解性能和热稳定性。层柱皂石的异丙苯裂解转化率达到了65%;而层柱蒙脱土的转化率只有4%。这说明层材料的四面体取代对于层柱粘土Br?nsted酸位的形成具有重要的决定作用。氨程序升温脱附实验发现铝柱皂石在350~650 ℃区间具有较强的氨脱附量,表明层柱皂石具有层柱蒙脱土所没有的强酸中心。  相似文献   

8.
用失重和表面腐蚀层厚度的测定以及借助于X光电子能谱(XPS)、红外吸收光谱(FT—IR)、扫描电子显微镜(SEM)等分析手段研究芳烷基酚树脂在浓硫酸中的腐蚀行为。探讨耐浓硫酸腐蚀机理模型。结果表明试样经一定时间浸泡后表面腐蚀层厚度对温度和作用时间没有依赖关系,该材料耐浓硫酸腐蚀。腐蚀机理为:浸泡过程中,试样表面形成了一层结构致密的耐腐蚀物质,阻止了硫酸分子进一步向试样内部扩散渗透,使试样内部免遭进一步破坏。  相似文献   

9.
磷的掺杂对碳负极材料性能的影响   总被引:2,自引:0,他引:2  
研究了磷酸的引入对以聚丙烯腈为基体碳负极材料性能的影响.元素分析、XPS及XRD分析结果表明,磷在碳材料中与碳及氧原子相结合.磷酸的引入在较低的温度(600℃)下有利于聚丙烯腈-CN基的环化、脱氢碳化过程,使氮的含量及graphene氮的相对含量增加,磷的键合使碳材料的层间距反而增加,因此位于0.9V以上及以下的可逆容量均随磷酸的加入量的增加而增加,总的可逆容量高达524mAh/g.而在较高的温度(1000℃)下,碳化程度变化不大,主要表现为磷原子的掺杂效果,其引入使位于1.0V左右的可逆容量增加  相似文献   

10.
层柱材料(如层柱粘土、金属磷酸盐等)因其有独特的物理化学性质而倍受人们青睐,并其中;层柱金属氧化物是一类近年来才开发的新型层柱材料.由于制备上的困难,迄今所报导的层柱金属氧化物为数甚少,K0.8Ti1.2O4是一个典型的层状金属氧化物,但由于期没有遇水溶胀性,用常规方法无法制备热稳定的无机氧化物柱层状铁钛酸盐.本文通过先将K0.8Ti1.2O4同n-CH3(CH2)5NH3Cl反应得到正已铵离子柱撑的层状铁钛酸盐,然后再与NH2(CH2)3Si(OC2HO)3(以下简称APS)反应,最后将所得产物在空气中焙烧可得新型氧化硅柱层状铁钛酸盐,该新材…  相似文献   

11.
The adsorption and/or decomposition pathway of Fe2(CO)9 or Fe3(CO)12 on hydrated or dehydrated NaY zeolites has been studied by an ESR technique. The adsorption resulted in the formation of three paramagnetic species withg iso=2.0450, 2.0378, and 2.0016, which were attributable to Fe3(CO)11 , Fe2(CO)8 , and Fe(CO)4 anion radicals, respectively. These radicals have been suggested as intermediates in the formation of HFe3(CO)11 on the hydrated NaY zeolite and Fe3(CO)12 on the dehydrated NaY zeolite.  相似文献   

12.
Single-pulse 13C NMR spectra and spin-lattice relaxation times T1(1H), detected indirectly via 13C carbons, and T1(13C) were measured at 31°C for virgin pelletized and annealed polylactic acid (PLA) samples using the magic-angle spinning technique. The structural relaxation resulting in more regular crystals with narrower conformation distribution and increase in the lamellae thickness and crystallinity brought about by annealing at 100°C was deduced from the narrowing of the 13C NMR lines and proton spin-lattice relaxation times T1(1H). The spin-lattice relaxation times T1(13C) related to the respective carbons of the α-polymorph of PLA are also discussed in the study.  相似文献   

13.
《Journal of Coordination Chemistry》2012,65(16-18):2557-2568
Abstract

Reaction between (E)-2-((pyridin-2-ylimino)methyl)phenol (HL) and copper(II) nitrate provides tetrakis{(E)-2-((pyridin-2-ylimino)methyl)phenolato}(hydroxido)0.5(nitrato)1.5-tetracopper(II) nitrate hydroxide, [(CuL)4(NO3)1.5(OH)0.5](NO3)(OH) (1 (a) J. Miao, Z. Zhao, H. Chen, D. Wang, Y. Nie. Acta Cryst., E65, m904 (2009); (b) A. Castineiras, J.A. Castro, M.L. Duran, J.A. Garcia-Vazquez, A. Macias, J. Romero, A. Sousa. Polyhedron, 8, 2543 (1989); (c) I.S. Vasil'chenko, A.S. Antsyshkina, D.A. Garnovskii, G.G. Sadikov, M.A. Porai-Koshits, S.G. Sigeikin, A.D. Garnovskii. Koord. Khimiya, 20, 824 (1994).[Crossref], [Web of Science ®] [Google Scholar][Google Scholar][Google Scholar]). ESI-mass spectra show the ion peaks for the dinuclear species at m/z 565 for [(CuL)2(HCO2)]+ and 521 for [(CuL)2+H]+ and the mononuclear species at m/z 260 for [(CuL)]+. Vibrational spectra show very strong bands at 1604/1546?cm?1 for ν(C?=?N/C?=?C) and at 1384, 1351?cm?1 for ν(NO3). Cyclic voltammograms demonstrate an irreversible redox processes for the Cu(II)/Cu(I) and Cu(I)/Cu(0) couples in acetonitrile. X-ray molecular structure determination explores the formation of a cationic tetranuclear copper(II)-complex, in which a deprotonated ligand molecule chelates to one copper ion with the phenolate-O and imino-N atoms. In addition, a phenolate-O atom bridges between two neighboring copper ions and a pyridine-N atom coordinates to a third copper ion, so that each ligand bridges among three copper ions in a κ2N,O:κO:κN' coordination sphere. Thus, the four copper ions and four chelating-bridging ligands assemble primarily into a cationic [(CuL)4]4+ complex. The two copper ions are further coordinated by either a nitrate anion (75% occupancy) or a hydroxide anion (25% occupancy) and form the core of a tetranuclear [(CuL)4(NO3)1.5(OH)0.5]2+ cation.  相似文献   

14.
The reaction of (E,E,E)-2,6,10-cyclododecatrien-1-yl acetate with 2-methoxyethanol catalyzed by Pd0(PPh3)4 was studied in tetrahydropyran solutions at 358K. The selectivity of the unsaturated ether at conversion of allyl acetate up to 68.1% ranged within 92.1–98.5%. The product composition was related to kinetic equations which can be used for reactor design.  相似文献   

15.
The possibilities of stabilizing emulsions by means of proteins and polysaccharides have been discussed. It is shown that the use of anionic polysaccharides makes it possible to increase considerably the stability of protein-containing emulsions. The developed methods of stabilizing emulsions by means of anionic polysaccharides are protein-universal and useful for the preparation of emulsions based on phases of different polarity. The use of these methods allows to avoid the use of low-molecular surfactants for the preparation of protein-containing C/W emulsions.  相似文献   

16.
17.
分别利用微乳液水热法和酸蒸气水热法合成了杂多蓝化合物ZrW1.7ⅥW0.3ⅤO7H0.3(OH)2·2H2O.XRD测定结果表明,该化合物与ZrMo2O7(OH)2·2H2O具有相同晶体结构类型.使用Rietveld方法对产物进行了结构精修,并计算出了键参数和键价.运用EPR技术测定了该化合物中W的价态,并利用XPS能谱测定了W/W的比例.利用价键和规则,指出ZrW1.7ⅥW0.3ⅤO7H0.3(OH)2·2H2O中的W—O3—H0.15存在羟基化现象,并对杂多蓝化合物的红外吸收光谱进行了指认.  相似文献   

18.
The reaction of methylene radicals in their 3 B1 electronic ground state with molecular NO was studied. Pure CH2(X 3 B1 ) radicals were produced by UV photolysis of ketene at 351 nm. The products were measured by Time-Resolved Fourier Transform Infrared (TR-FTIR) spectrometer. CO.OH .NH2 and HOCN or its isomer HNCO were found as primary products and several possible channels of this reaction were suggested.  相似文献   

19.
合成了两种稀土高氯酸盐与L 脯氨酸配合物的晶体.经热重、差热、化学分析及对比有关文献,知其组成是[Pr2(L Pro)6(H2O)4](ClO4)6和[Er2(L Pro)6(H2O)4](ClO4)6,质量分数为99.24%和98.20%.选用RE(NO3)3•6H2O(RE=Pr,Er)、L Pro、NaClO4•H2O和NaNO3作辅助物,使用具有恒温环境的反应热量计,以2 mol•L-1 HCl作溶剂,分别测定了[2RE(NO3)3•6H2O+6L Pro+6NaClO4•H2O]和{[RE2(L PrO)6(H2O)4](ClO4)6+6NaNO3}在298.15 K时的溶解热.设计一热化学循环求得化学反应的反应焓ΔrHm分别是:63.904 kJ•mol-1和91.017 kJ•mol-1,经计算得配合物[RE2(L Pro)6(H2O)4](ClO4)6(s)在298.15 K时的标准生成焓ΔfHm(298.15 K)分别是-6 594.78 kJ•mol-1和-6 532.87 kJ•mol-1.  相似文献   

20.
The synthesis, crystal structures, electrochemical, and magnetic properties of a linear pentanuclear Ni5 compound derived from an oligo-α-pyridylamino ligand, [Ni5(μ-dmpdda)4(NCS)2] [dmpdda-H2 = N,N′-di(4-methylpyridin-2-yl)pyridine-2,6-diamine], are reported. Ni5(μ-dmpdda)4(NCS)2 involve a Ni5 linear chain unit with all of the Ni–Ni–Ni angles being nearly 180°, terminated by two axial ligands. The pentanuclear linear metal chain is helically wrapped by four synsynsynsyn type dmpdda2? ligands. There are two types of Ni–Ni distances in this complex. Terminal Ni–Ni distances bonded with the axial ligand are longer (2.377 Å); the inner Ni–Ni distances are short at 2.2968 Å. Terminal Ni(II) ions bonded with the axial ligands are square-pyramidal (NiN4NCS) with long Ni–N bonds (2.092 Å), consistent with a high-spin Ni(II) configuration. The inner three Ni(II) ions have short Ni–N (1.901–1.925 Å) bond distances, consistent with a square planar (NiN4), diamagnetic arrangement of a low-spin Ni(II) configuration. This compound exhibits magnetic behavior similar to [Ni5(μ-tpda)4(NCS)2], indicating an antiferromagnetic interaction of two terminal high-spin Ni(II) ions.  相似文献   

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