Removal of NOx and Diesel Soot Particulates Catalyzed by Perovskite-type Oxide La0.9K0.1CoO3

1 IntroductionTeraoka and Shangguan,etchaveresearchedthereac-tion between tight soot and catalyst mixture with tempera-ture increase[1-5].Their results confirmedthat the La0 .9K0 .1CoO3perovskite type composite oxide are excellent catalystwhich can simultaneously remove diesel particulate matterand NOx[3 ,4].We have researchedthetraditional solidstatereaction method and sol-gel methodfor preparation of La0 .9K0 .1CoO3perovskite composite oxide[6].The results showsthat for boththe method t…     

The use of SIMS to investigate the incorporation of oxygen in CoO scales

SIMS was used to locate O¹⁸ in a thick oxide scale grown on a cobalt specimen oxidized first in O¹⁶ and subsequently in O¹⁸. Analyses were performed in depth profile from the oxide-gas interface and in step scan across a polished cross section. SIMS was found to be well suited to this type of oxygen tracer study. Eighty percent of the O¹⁸ was located in the inner quarter of the scale with a maximum value of 70% 10–15 from the metal-oxide interface. The distribution of the remaining O¹⁸ was essentially uniform in the outer 3/4 of the scale at an average value of 4.6%. There was, however, a layer 150 nm thick highly enriched in O¹⁸ at the oxide-gas interface. The O¹⁸ in the outer 3/4 of the porous scale is probably the result of normal exchange processes. The form of the distribution near the metal-oxide interface cannot be explained at this time.     

Effect of CoO Addition on Electrochemical Properties of La0.7Mg0.3 （Ni0. 85 Co0. 15 ） 3.5 Hydrogen- Storage Alloy

In order to improve the cycling stability of La-Mg-Ni-Co hydrogen storage alloys, the La0.7Mg0.3 （Ni0.85Co0.15）3.5 alloy was prepared by inductive melting under argon atmosphere. The effect of additive CoO on electrochemical properties of La0.7Mg0.3（Ni0.85 Co0.15）3.5 alloy, which is used as an electrode material was studied. When the addition of CoO is 5 %, both the discharge capacity at high-, low- and room-tem- perature and charge-discharge cycling stability at room temperature can be significantly improved. Electro- chemical measurements and X-ray diffraction （XRD） analyses suggest that CoO improves the electrochemical properties of the La0.7Mg0.3（Ni0.85Co0.15）3.5 alloy by promoting the electrochemical reaction of another phase in the alloy and by self electrochemical reversible reaction occurring during the charge-discharge process.     

层状Li_(0.5)Na_(0.5)CoO_2的合成及显微结构

为了研究具有α-Na Fe O2结构的复杂钴氧化物原子排列规律,采用固相反应合成了Li0.5Na0.5Co O2多晶粉末,并利用X射线衍射(XRD)、扫描电子显微分析(SEM)和透射电子显微分析(TEM)等检测手段对其形貌、晶体结构等进行了表征。结果表明:一般处理状态下,Li0.5Na0.5Co O2为片状,其晶体结构与层状Li Co O2相似,但在某些处理状态下通过TEM观察到沿[0001]带轴衍射花样中出现菱面体晶系中应该消光{10 1 0}的晶面族。这说明Li0.5Na0.5Co O2的晶体结构已经由菱面体结构转变成六方结构。     

CoO掺杂对15(20Ni-Cu)/(NiO-NiFe2O4)金属陶瓷导电性能的影响

在15(20Ni-Cu)/(NiO-NiFe2O4)金属陶瓷中掺杂CoO,制备15(20Ni-Cu)/[10(xCoO-yNiO)-9ONiFe2O4]金属陶瓷,研究CoO掺杂量x对15(20Ni-Cu)/(NiO-NiFe2O4)金属陶瓷材料的烧结致密化、物相组成以及电导率的影响.结果表明:当CoO掺杂量x为0～10...     

CoO纳米颗粒的制备及磁性研究

用聚乙烯醇溶胶-凝胶法制备出氧化钴(CoO)纳米颗粒。分析了胶体浓度、热处理温度和时间对制备CoO纳米颗粒工艺的影响。用X射线衍射仪和透射电子显微镜对样品的形貌、结构和物相进行了测试，用振动样品磁强计初步探讨了CoO纳米颗粒在室温下的磁性。结果发现胶体浓度为2：1时有利于形成CoO纳米颗粒，在氢气环境下对干胶进行煅烧时生成CoO纳米颗粒的温度范围在225～350℃之间。CoO纳米颗粒的结构为NaCl结构。在较低温度下烧结干胶时发现颗粒尺寸随着热处理时间的增加变化不大。用此方法制备的CoO纳米颗粒直径最小约为12nm。在室温下表现为类似于超顺磁性的特征。     

添加剂CoO对超电容器用电极材料--改性氮化钼电极性能的影响

MoO3和CoO混合物与NH3通过程序升温反应,运用XRD和SEM对氮化产物———电极材料进行表征和表面形貌研究。结果表明氮化产物中有Co3N的生成,添加CoO后,电极成膜物质的晶粒规整化程度提高,生成了γMo2 N纳米级的晶体。γMo2 N及其复合电极循环伏安法测量表明,复合电极具有较好的稳定性和重现性。相同条件下,复合电极比电容是未加添加剂的2倍,工作电势拓宽0 3V。     

MOD法在LaAlO3单晶上沉积La0.4Sr0.6CoO3导电缓冲层

用金属有机物沉积(MOD)法在LaAlO3(100)单晶基底上制备了立方钙钛矿型导电缓冲层La0.4Sr0.6CoO3(LaSrCoO)薄膜。根据热分析曲线确定前驱膜的热处理工艺,其中前驱膜的热分解温度为620～800℃,涂膜的结晶温度为825℃。由X射线衍射(XRD)分析可知,热处理后涂膜的主相是LaSrCoO,其择优取向为<100>;另外还有La2CO5和LaCoO3等杂相。由φ扫描和(100)极图可知,所制备的涂膜有较强双轴织构。用标准四引线法测量了涂膜的室温和低温电阻率,在77K时达到1.04×10-4?·m,实现了沉积导电缓冲层的目的。     

Ag/CoO纳米复合薄膜的制备及其光吸收特性研究

通过溶胶凝胶法制备了不同掺杂浓度的Ag/CoO纳米复合薄膜.利用DTA-TG研究了CoO干凝胶的分解温度和分解产物,初步确定了退火温度为600 ℃,气氛为N_2.X射线衍射分析表明:薄膜中存在Ag和CoO两相.在300～800 nm范围内的吸收光谱表明,Ag/CoO复合薄膜在410 nm波长左右出现显著的表面等离子共振吸收峰,并且随着Ag含量的增加,吸收峰不断增强,其吸收峰位先蓝移后红移.当Ag含量(质量分数,下同)为40%时,吸收峰最强,继续增加Ag的含量,吸收峰强度开始下降.计算光学带隙,证明并解释了吸收峰移动.     

Synthesis,sintering, and thermoelectric properties of Co1-xMxO (M = Na, 0 ≤ x ≤ 0.07; M = Ag, 0 ≤ x ≤ 0.05)

The structural and thermoelectric properties of Na- and Ag-substituted CoO dense ceramics have been investigated. X-ray diffraction shows that pure phase and Ag/CoO composites have been obtained for Na-doped and Ag-doped CoO, respectively. Raman spectroscopy shows an effect of Na dopants on the lattice disorder of CoO. The chemical composition, element distribution, and valence states of the samples have been characterized by Auger electron microscopy and X-ray photoelectron spectroscopy. Substitution of Co by 5 at. % Na enhances the power factor to 250 μW m⁻¹ K^-2 at 1000 K, similar to that of Ca₃Co₄O₉. The corresponding thermal conductivity is also reduced to 3.55 W.m⁻¹ K⁻¹ at 1000 K. Consequently, Co_0.95Na_0.05O exhibits the best thermoelectric figure of merit (ZT), which is 0.07 at 1000 K. On the other hand, the substitution of Ag into CoO leads to the formation of CoO/Ag composites and deteriorates ZT values.