新型固体电解质La2Mo2O9的制备及其性能

用固相法制备了新型固体电解质La2Mo2O9, 用热膨胀仪、 X射线衍射仪和Raman光谱分析了La2Mo2O9相的形成过程. 用交流阻抗谱和热膨胀仪对合成样品的电学和热学性能进行了研究, 分析了热处理温度对La2Mo2O9相的形成过程和电学性能的影响, 确定了样品获得高电学性能的最佳条件. 研究结果表明: 600 ℃时样品中开始形成La2Mo2O9相, 700 ℃以上烧结的样品可获得具有完整氧空位的La2Mo2O9相. 900 ℃烧结10 h可获得具有高密度和高电导率的La2Mo2O9氧离子导体. 样品的电学性能随烧结温度的升高而增大, 900 ℃时烧结的样品在800 ℃时的电导率为0.067 S·cm-1, 远高于同温度下YSZ的电导率, 与晶粒电阻相比, 晶界电阻非常小. 用热膨胀仪测得La2Mo2O9在555 ℃时有一个一级相变, 对应α-La2Mo2O9到β-La2Mo2O9的相变.     

MnO2掺杂金属陶瓷惰性阳极的制备及性能研究

以氧化铝-金属复合材料为基质, 通过掺杂MnO2制备一种新型电解铝所用的陶瓷惰性阳极, 并对添加MnO2的阳极材料的综合性能进行了考察. 研究了MnO2对烧结性能的影响, 并对样品进行了静态腐蚀实验的研究, 测定了样品在500~1000 ℃下电导率随温度的变化. 研究结果表明, 添加MnO2有利于材料烧结且能改善材料的物化性能: 烧结样品晶粒生长完整, 致密度高; 耐高温和抗冰晶石熔盐腐蚀性能好, 平均腐蚀速率降为12.32 mm/year; 导电性能稳定、良好, 具有半导体的导电性质, 电导率随温度的升高而增大, 测得850 ℃时样品的电导率为67 S/cm.     

YxTi2On(1.7≤x≤2.1)系固态电解质的共沉淀法合成及电导率研究

以TiCl3、YCl3溶液和氧化钛、氧化钇为原料,通过共沉淀法和固相法制备了YxTi2On(1.7≤x≤2.1,x=1.7,1.8,1.9,2.0,2.1)系烧绿石型固态电解质样品。粉体经700℃处理后在透射电镜下可见其粒径小于100 nm的晶粒。用共沉淀法制得的样品通过1500℃/5 h烧结后的相对密度近94%,且比用固相法经1550℃/5 h烧结所获相同组成样品的相对密度明显要高。X衍射表明样品A(x=1.7)的主晶相为烧绿石和二氧化钛,而样品D(x=2.0)和E(x=2.1)都为烧绿石。从扫描电镜照片可见,样品E的晶界随着烧结温度的提高变得更清晰,晶体生长也更充分。随着Y2O3含量的增加,YxTi2On(1.7≤x≤2.1)系电解质的电导率随之增加。用共沉淀法所得样品的电导率明显高于相应固相法所得样品。随烧结温度和测量温度的提高,样品E的电导率增加。     

真空注浆法制备YSZ电解质膜管及其在固体氧化物燃料电池中的应用

以吡啶为分散剂，采用真空注浆法制备出膜厚为0．2mm，长度为140mm的致密YSZ电解质膜管，研究了烧结中温度对样品致密度和离子导电率的影响，用1650℃烧结2h制备的致密YSZ电解质膜管组装成固体氧化物燃料电池，以氢气和煤气为燃料，研究了电池在500－900℃的电化学性能，实验结果表明，用真空注浆法可制备出高质量和高密度的YSZ电解质膜管，在1600℃烧结后，其相对密度已达到理论密度的98．1％，接近理论密度，单电池的开路电压最大值为1．213V，最大输出功率为0．48W，以氢气为燃料的燃料电池性能明显高于以煤气为燃料的电池性能。     

湿化学法合成钙钛矿结构中温电解质La0.8Sr0.2Ga0.85Mg0.15O3-δ及其性能研究

以尿素-硝酸盐为前驱体合成了具有钙钛矿结构的中温电解质La0.8Sr0.2Ga0.85Mg0.15O3-?(LSGM)。用DTA-TG和XRD分析了样品中钙钛矿相的形成过程。用热膨胀仪确定了LSGM的烧结温度及热膨胀系数。用交流阻抗谱研究了所获得LSGM样品的电学性能。研究结果表明：用尿素-硝酸盐合成LSGM的成相温度为1300， 1500 ℃烧结6 h可获得单相的LSGM样品。用尿素-硝酸盐合成LSGM样品的烧成温度为1485 ℃，明显低于固相法合成LSGM的烧成温度。 1500 ℃烧结6 h的LSGM样品在850 ℃时的电导率为5×10-2 S·cm-1，高于同温下钇稳定化氧化锆(YSZ)样品的电导率，表明LSGM更适合做中温SOFC的电解质材料。在30～1000 ℃的温度范围内， LSGM的膨胀系数为12.8×10-6 ℃-1。     

Sm2O3掺杂金属陶瓷惰性阳极的制备及性能研究

采用氧化铝-金属复合材料,适量掺杂稀土金属氧化物（Sm2O3）,制备一种新型铝电解用氧化铝基金属陶瓷惰性阳极,并对添加稀土氧化物的材料综合性能进行了研究.结果表明： 添加稀土氧化物的试样晶粒生长完整,致密度高,耐高温和抗冰晶石熔盐腐蚀性能良好,年平均腐蚀速率为12.27 mm; 导电性能稳定、良好,其电导率随温度的升高而增大,具有半导体的导电性质,850 ℃时测得添加稀土氧化物的试样电导率为63 S·cm^-1.     

Sm0.5Sr0.5Co1-xCuxO3-δ阴极材料的合成与性能研究

采用尿素-硝酸盐法制备了Sm0.5Sr0.5Co1-xCuxO3-δ(x=0～0.5)阴极材料.用TG-DSC,SEM,XRD和热膨胀仪对材料的形成过程、晶体结构、烧结体的微观结构及热膨胀性能进行了表征.用直流四端子法测试材料在500～800℃范围内的电导率.结果表明,制备样品的主晶相为正交钙钛矿结构,体系含有杂相;电导率随温度和Cu含量的变化关系表现为,x≤0.2时的样品随温度升高电导率降低,x≥0.3时随温度升高电导率增大,组成为x=0.2的样品电导率最高,500℃达到703.1 S·cm-1.材料的热膨胀系数随掺杂的Cu含量增加而降低.     

Ce_(1-x)Ca_xO_(2-x)的溶胶-凝胶法的合成及其性质

用溶胶 -凝胶法合成了 Ce1-x Cax O2 -x(x=0～ 0 .3 5 )系列固体电解质 ,系统地研究了其晶体结构随Ca O含量的变化关系 .XRD测试表明 ,该体系于 1 60℃即形成萤石结构纯相 .高温 XRD表明 ,从室温至80 0℃ ,Ce1-x Cax O2 -x(x=0～ 0 .3 5 )未出现结构相变 .此法合成温度远低于传统的高温固相合成法和水热合成法的温度 .合成物的颗粒小 ,粒度均匀 .在 1 3 0 0℃即可烧结成高致密度样品 .XPS测试表明 ,掺杂 Ca O后吸附氧浓度明显增大 ,氧空位增多 ,电导率和氧离子迁移数增大 ,改善了 Ce O2 基固体电解质的性能 .     

新型导电陶瓷Sm_0.9St_0.1Al_0.5Mn_0.5O_(3-δ)的制备及其电性能研究

采用有机凝胶法结合固相烧结技术制备了Sm_0.9St_0.1Al_0.5Mn_0.5O_(3-δ)(SSAM9 155)新犁导电陶瓷.通过TG/DTA,FTIR, XRD,SEM和直流四引线法系统研究了凝胶前驱体的热分解及其相转化过程和烧结体的结构、相稳定性、微观形貌、电导率以及电输运机制.结果表明,凝胶前驱体在900℃焙烧5 h可以形成完全晶化的四方钙钛矿相纳米粉体;高温烧结制得的SSAM9155陶瓷的电导率取决于P型电导,电导率随温度的升高而增大,导电行为符合P型小极化子跳跃机制;随烧结温度的升高或保温时间的延长,SSAM9155陶瓷的电导率和相对密度都先增大后减小,1600℃烧结10 h制得的SSAM9155陶瓷具有最高的电导率和相对密度(98%),该样品在空气和氢气气氛中850℃时的电导率分别为8.21和1.26 S·cm~(-1),表观活化能分别为0.265和0.465 eV.具有较高电导率的Sr,Mn掺杂的SmAlO_3导电陶瓷有望成为一种新型的固体氧化物燃料电池(SOFC)阳极材料.     

复合电解质Ce0.8Gd0.2O2-α-(Li/K)2CO3的中温燃料电池性能

用溶胶凝胶法低温(900℃,通常高温烧结温度为1400℃)制备了Ce_(0.8)Gd_(0.2)O_(2-α),并与(Li/K)_2CO_3共熔体进行复合。XRD结果表明(Li/K)_2CO_3与Ce_(0.8)Gd_(0.2)O_(2-α)复合后没有发生化学反应,SEM结果表明复合电解质致密无孔洞。考察了复合电解质在400~600℃下干燥氮气气氛中的电导率,结果表明,温度为600℃时,复合电解质的电导率达到最大值6.4×10~(-2)S·cm~(-1),高于单一CeO_2材料在相同条件下的电导率。氧分压与电导率关系曲线表明复合电解质具有良好的氧离子导电性。H_2/O_2燃料电池性能测试表明,复合电解质GDC-SG-LK在600℃开路条件下的电解质阻抗、极化阻抗分别为2.7和0.8Ω,最大输出功率密度为267mW·cm~(-2)。     

Rhodium-catalyzed dehydrocoupling of the sterically encumbered phosphine-borane adduct tBu(2)PH.BH(3): synthesis of the linear dimers tBu(2)PH-BH(2)-tBu(2)P-BH(3) and tBu(2)PH-BH(2)-tBu(2)P-BH(2)Cl

The dehydrocoupling of the sterically hindered phosphine-borane adduct tBu(2)PH.BH(3) above 140 degrees C is catalyzed by the rhodium complexes [Rh(1,5-cod)(2)][OTf] or Rh(6)(CO)(16) to give the four-membered chain tBu(2)PH-BH(2)-tBu(2)P-BH(3) (1), which was isolated in 60% yield and characterized by multinuclear NMR spectroscopy, mass spectrometry, and elemental analysis. Thermolysis of 1 in the temperature range 175-180 degrees C led to partial decomposition and the formation of tBu(2)PH.BH(3). When the dehydrocoupling of tBu(2)PH.BH(3) was performed in the presence of [[Rh(mu-Cl)(1,5-cod)](2)] or RhCl(3) hydrate, the chlorinated compound tBu(2)PH-BH(2)-tBu(2)P-BH(2)Cl (2) was formed which could not be obtained free of 1. The molecular structures of tBu(2)PH.BH(3), tBu(2)PH-BH(2)-tBu(2)P-BH(3) (1), and tBu(2)PH-BH(2)-tBu(2)P-BH(2)Cl (2) together with 1 were determined by single-crystal X-ray diffraction studies.     

New layered materials: syntheses, structures, and optical properties of K(2)TiCu(2)S(4), Rb(2)TiCu(2)S(4), Rb(2)TiaAg(2)S(4), Cs(2)TiAg(2)sS(4), and Cs(2)TiCu(2)Se(4)

The new compounds K(2)TiCu(2)S(4), Rb(2)TiCu(2)S(4), Rb(2)TiAg(2)S(4), Cs(2)TiAg(2)S(4), and Cs(2)TiCu(2)Se(4) have been synthesized by the reactions of A(2)Q(3) (A = K, Rb, Cs; Q = S, Se) with Ti, M (M = Cu or Ag), and Q at 823 K. The compounds Rb(2)TiCu(2)S(4), Cs(2)TiAg(2)S(4), and Cs(2)TiCu(2)Se(4) are isostructural. They crystallize with two formula units in space group P4(2)/mcm of the tetragonal system in cells of dimensions a = 5.6046(4) A, c = 13.154(1) A for Rb(2)TiCu(2)S(4), a =6.024(1) A, c = 13.566(4) A for Cs(2)TiAg(2)S(4), and a =5.852(2) A, c =14.234(5) A for Cs(2)TiCu(2)Se(4) at 153 K. Their structure is closely related to that of Cs(2)ZrAg(2)Te(4) and comprises [TiM(2)Q(4)(2)(-)] layers, which are separated by alkali metal atoms. The [TiM(2)Q(4)(2)(-)] layer is anti-fluorite-like with both Ti and M atoms tetrahedrally coordinated to Q atoms. Tetrahedral coordination of Ti(4+) is rare in the solid state. On the basis of unit cell and space group determinations, the compounds K(2)TiCu(2)S(4) and Rb(2)TiAg(2)S(4) are isostructural with the above compounds. The band gaps of K(2)TiCu(2)S(4), Rb(2)TiCu(2)S(4), Rb(2)TiAg(2)S(4), and Cs(2)TiAg(2)S(4) are 2.04, 2.19, 2.33, and 2.44 eV, respectively, as derived from optical measurements. From band-structure calculations, the optical absorption for an A(2)TiM(2)Q(4) compound is assigned to a transition from an M d and Q p valence band (HOMO) to a Ti 3d conduction band.     

Diverse evolution of [[Ph(2)P(CH(2))(n)PPh(2)]Pt(mu-S)(2)Pt[Ph(2)P(CH(2))(n)PPh(2)]] (n = 2, 3) metalloligands in CH(2)Cl(2)

The nucleophilicity of the [Pt(2)S(2)] core in [[Ph(2)P(CH(2))(n)PPh(2)]Pt(mu-S)(2)Pt[Ph(2)P(CH(2))(n)PPh(2)]] (n = 3, dppp (1); n = 2, dppe (2)) metalloligands toward the CH(2)Cl(2) solvent has been thoroughly studied. Complex 1, which has been obtained and characterized by X-ray diffraction, is structurally related to 2 and consists of dinuclear molecules with a hinged [Pt(2)S(2)] central ring. The reaction of 1 and 2 with CH(2)Cl(2) has been followed by means of (31)P, (1)H, and (13)C NMR, electrospray ionization mass spectrometry, and X-ray data. Although both reactions proceed at different rates, the first steps are common and lead to a mixture of the corresponding mononuclear complexes [Pt[Ph(2)P(CH(2))(n)PPh(2)](S(2)CH(2))], n = 3 (7), 2 (8), and [Pt[Ph(2)P(CH(2))(n)PPh(2)]Cl(2)], n = 3 (9), 2 (10). Theoretical calculations give support to the proposed pathway for the disintegration process of the [Pt(2)S(2)] ring. Only in the case of 1, the reaction proceeds further yielding [Pt(2)(dppp)(2)[mu-(SCH(2)SCH(2)S)-S,S']]Cl(2) (11). To confirm the sequence of the reactions leading from 1 and 2 to the final products 9 and 11 or 8 and 10, respectively, complexes 7, 8, and 11 have been synthesized and structurally characterized. Additional experiments have allowed elucidation of the reaction mechanism involved from 7 to 11, and thus, the origin of the CH(2) groups that participate in the expansion of the (SCH(2)S)(2-) ligand in 7 to afford the bridging (SCH(2)SCH(2)S)(2-) ligand in 11 has been established. The X-ray structure of 11 is totally unprecedented and consists of a hinged [(dppp)Pt(mu-S)(2)Pt(dppp)] core capped by a CH(2)SCH(2) fragment.     

Polydentate N(2)S(2)O and N(2)S(2)O(2) Ligands as Alcoholic Derivatives of (N,N'-Bis(2-mercaptoethyl)-1,5-diazacyclooctane)nickel(II) and (N,N'-Bis(2-mercapto-2-methylpropane)-1,5-diazacyclooctane)nickel(II)

The synthesis, structural characterization, spectroscopic, and electrochemical properties of N(2)S(2)-ligated Ni(II) complexes, (N,N'-bis(2-mercaptoethyl)-1,5-diazacyclooctane)nickel(II), (bme-daco)Ni(II), and (N,N'-bis(2-mercapto-2-methylpropane)1,5-diazacyclooctane)nickel(II), (bme-daco)Ni(II), derivatized at S with alcohol-containing alkyl functionalities, are described. Reaction of (bme-daco)Ni(II) with 2-iodoethanol afforded isomers, (N,N'-bis(5-hydroxy-3-thiapentyl)-1,5-diazacyclooctane-O,N,N',S,S')halonickel(II) iodide (halo = chloro or iodo), 1, and (N,N'-bis(5-hydroxy-3-thiapentyl)-1,5-diazacyclooctane-N,N',S,S')nickel(II) iodide, 2, which differ in the utilization of binding sites in a potentially hexadentate N(2)S(2)O(2) ligand. Blue complex 1 contains nickel in an octahedral environment of N(2)S(2)OX donors; X is best modeled as Cl. It crystallizes in the monoclinic space group P2(1)/n with a = 12.580(6) ?, b = 12.291(6) ?, c = 13.090(7) ?, beta = 97.36(4) degrees, and Z = 4. In contrast, red complex 2 binds only the N(2)S(2) donor set forming a square planar nickel complex, leaving both -CH(2)CH(2)OH arms dangling; the iodide ions serve strictly as counterions. 2 crystallizes in the orthorhombic space group Pca2(1) with a = 15.822(2) ?, b = 13.171(2) ?, c = 10.0390(10) ?, and Z = 4. Reaction of (bme-daco)Ni(II) with 1,3-dibromo-2-propanol affords another octahedral Ni species with a N(2)S(2)OBr donor set, ((5-hydroxy-3,7-dithianonadiyl)-1,5-diazacyclooctane-O,N,N',S,S')bromonickel(II) bromide, 3. Complex 3 crystallizes in the orthorhombic space group Pca2(1) with a = 15.202(5) ?, b = 7.735(2) ?, c = 15.443(4) ?, and Z = 4. Complex 4.2CH(3)CN was synthesized from the reaction of (bme-daco)Ni(II) with 1,3-dibromo-2-propanol. It crystallizes in the monoclinic space group P2/c with a = 20.348(5) ?, b = 6.5120(1) ?, c = 20.548(5) ?, and Z = 4.     

(2-Chlorobenzyl)tris(2-pyridinethiolato)tin(IV)

In the title compound, (2-chloro­benzyl)­tris­(pyridine-2-thiol­ato)-κ²N,S;κ²N,S;κS-tin(IV), [Sn(C₇H₆Cl)(C₅H₄NS)₃], two of the three pyridine-2-thiol­ato ligands (SPy) are bidentate and one is monodentate. The bonding C atom of the 2-chloro­benzyl group, the S atom of the monodentate SPy and the S and N atoms of the two bidentate SPy ligands form a distorted octahedron around the Sn atom. The three S atoms and the N atom of one of the bidentate SPy ligands occupy the equatorial positions, while the N atom of the second bidentate SPy ligand and the C(CH₂) atom are axial. The axial N—Sn—C angle of 157.9 (1)° demonstrates the heavy distortion of the octahedron.     

Synthesis and Structural Characterization of Cu（pic）2[CO（NH2）2]2 and （picH2）2[Cu（pic）2（SCN）2]

1 INTRODUCTION The picolinic acid (picH), also called pyridine- 2-carboxylic acid, has a broad spectrum of physio- logical effects on the activity functions of both ani- mal and plant organisms. It is attributed increasing interest due to its ability to …     

Infinite Three-Dimensional Coordination Polymers: Synthesis and Structures of [Cd (4,4''-bpy)2 (H2O)2]n (pic)2n, [Zn (4,4''-bpy)2 (H2O)2 ]n-(pic)2n (H2O)2n, and [Zn (4,4''-bpy)2 (H2O)2]n (4,4''-bpy)n (H2O)n (pic)2n

Recently, a new research realm in crystal engineering of supramolecular architecturesassembled by means of coordinate covalent bonding', hydrogen bonding', or other weakintermolecular interactions= has been rapidly expanding in order to rationally developnew classes of functional materials with cavities or pores. These types of compoundsmay exhibit interesting topological structures and the clathrations of the cavity structuresmay have many potential properties such as catalysis', electrical co…     

Transformation of organic molecules on the low-valent [M(Ph(2)PCH(2)CH(2)PPh(2))(2)] moiety derived from trans-[M(N(2))(2)(Ph(2)PCH(2)CH(2)PPh(2))(2)] or related complexes (M = Mo, W)

A zero-valent [M(Ph(2)PCH(2)CH(2)PPh(2))(2)] moiety (M = Mo, W) generated in situ by dissociation of the N(2) ligands in trans-[M(N(2))(2)(Ph(2)PCH(2)CH(2)PPh(2))(2)] can activate pi-accepting organic molecules including isocyanides and nitriles, which undergo the electrophilic attack caused by a strong pi-donation from a zero-valent metal center. Cleavage of a variety of C-X bonds (X = H, C, N, O, P, halogen) also occurs at their electron-rich sites through oxidative addition to form reactive intermediates, which subsequently degradate to yield smaller molecules either bound to or dissociated from the metal center. The mechanism is substantiated unambiguously by isolation of numerous intermediate stages.