Physicochemical compatibility of SrCeO3 with potential SOFC cathodes
摘要:
The chemical and physical compatibility of SrCeO3 is investigated with respect to LaMO3 (M = Mn, Fe, Co) and La2-x.SrxNiO4 (x = 0, 0.8) via the reaction of fine-grained powder compacts and solid-state diffusion Couples. Compositions were chosen so as to give predictive insight into possible candidate materials for all-oxide electrochemical devices. Results show the primary reaction in these systems to be the dissolution of SrO from SrCeO3 into the LaMO3/La2-xSrxNiO4, and corresponding formation of La-doped CeO2. Reaction kinetics are observed to be relatively fast, with element profiles Suggesting the diffusion of Sr2+ in ceria to be surprisingly rapid. It is demonstrated that perovskite starting materials represent poor candidates for use with SrCeO3, reacting completely to form Ruddlesden-Popper/K2NiF4 type oxides. Reaction with LaNiO4 is less pronounced, and formation of secondary phases suppressed for the composition La1.2Sr0.8NiO4. It is thus concluded that Ruddlesden-Popper type oxides represent good candidate materials for use with a SrCeO3-based electrolytes when doped with appropriate levels of Sr. (C) 2007 Elsevier Inc. All rights reserved.
A novel singlet oxygen involved peroxymonosulfate activation mechanism for degradation of ofloxacin and phenol in water
作者:Xike Tian、Panpan Gao、Yulun Nie、Chao Yang、Zhaoxin Zhou、Yong Li、Yanxin Wang
DOI:10.1039/c7cc02820b
日期:——
This study proposed a new and previously unconsidered reaction mechanism in the activation of peroxymonosulfate. We report that singlet oxygen (1O2) rather than ˙OH or SO4˙− was the dominant reactive oxygen species towards the efficient degradation of ofloxacin and phenol, demonstrating a promising application in real wastewater treatment.
这项研究提出了一种过氧化单硫酸盐活化中新的,以前尚未考虑的反应机理。我们报告,单线态氧(1 Ò 2),而不是OH或SO 4 ˙ -是朝着氧氟沙星和苯酚高效降解的主导活性氧,表明在实际的废水处理有希望的应用程序。
The intrinsic exchange bias effect in the LaMnO3 and LaFeO3 compounds
作者:Abd El-Moez A. Mohamed、Pablo Álvarez-Alonso、B. Hernando
DOI:10.1016/j.jallcom.2020.156713
日期:2021.1
antiferromagnetic (AFM) nature of these compounds. Nevertheless, an anomalous ferromagnetic (FM) behaviour is observed, which is more likely, arises from the spin canting effect in the Mn3+ and Fe3+ ions. The thermal variation of the magnetisation reciprocal (M−1) has confirmed the presence of this FM component below 110K in LaMnO3 and the Curie-Weiss behaviour above 160K. Also, the magnetic hysteresis loops below
Preparation of Nanosized Perovskite-type Oxides via Polyol Method
作者:M. Siemons、Th. Weirich、J. Mayer、Ulrich Simon
DOI:10.1002/zaac.200400300
日期:2004.10
Several perovskite-typenanosizedoxides were prepared via polyol-mediated synthesis. The crystallinity of the materials was analysed by X-ray diffraction (XRD). While the “as synthesized” materials are amorphous or show very poor crystallinity, highly ordered materials could be obtained by annealing at 700 °C. Morphology of the materials was analysed by scanning electron microscopy (SEM) and transmission
通过多元醇介导的合成制备了几种钙钛矿型纳米氧化物。通过X射线衍射(XRD)分析材料的结晶度。虽然“合成”材料是无定形的或显示出非常差的结晶度,但通过在 700 °C 下退火可以获得高度有序的材料。通过扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析材料的形态。材料的粒径介于 20 和 200 nm 之间。Darstellung nanopartikularer Oxide des Perowskittyps uber die Polyol-Methode Uber eine Polyol-vermittelte Synthese wurden mehrere nanoskalige Oxide mit Perowskitstruktur hergestellt。Die Kristallstruktur der Materialien wurden mittels Rontgendiffraktometrie
Catalytic Properties of Perovskite-Type Mixed Oxides (ABO<sub>3</sub>) Consisting of Rare Earth and 3d Transition Metals. The Roles of the A- and B-Site Ions
作者:Taihei Nitadori、Tatsumi Ichiki、Makoto Misono
DOI:10.1246/bcsj.61.621
日期:1988.3
(lanthanoid) elements, B=3d transition metals) for the oxidation of propane and methanol have been studied comparatively. It has been found that the catalytic activities of LnBO3 were principally determined by the B-site elements and were similar to those of the corresponding oxides of the B-site elements. The roles of the rare-earth ions of the A-site were secondary as long as they were trivalent. Upon the
比较研究了钙钛矿型混合氧化物(LnBO3 和 Ln0.8Sr0.2CoO3,Ln=稀土(镧系)元素,B=3d 过渡金属)对丙烷和甲醇氧化的催化活性。已经发现,LnBO3 的催化活性主要由 B 位元素决定,并且与 B 位元素的相应氧化物的催化活性相似。A 位的稀土离子的作用是次要的,只要它们是三价的。在用 Sr2+ 部分取代 Ln3+ 后,LnCoO3 的催化活性增加了数倍,所有稀土离子的增加幅度相似。这些结果表明,B 位金属的种类和价态对于控制氧化催化活性至关重要,
A comparative study on perovskite-type mixed oxide catalysts A$prime;xA1 $minus; xBO3 $minus; $lambda; (A$prime; = Ca, Sr, A = La, B = Mn, Fe, Co) for NH3 oxidation
作者:Y WU
DOI:10.1016/0021-9517(89)90253-4
日期:1989.11
Three series of samples having the stoichiometry A′xA1 − xBO3 − λ (x = 0 − 1, B = Mn, Fe, Co) were prepared and used as catalysts for NH3 oxidation. It was found that even at x = 0 or x = 1 the compositions of the catalysts were nonstoichiometric. The nonstoichiometric amount of oxygen, λ, with which the crystalstructure, defects in the solid, reactivity with reactant oxygen, and catalytic activity could
制备具有化学计量比A ′ × A 1 -x BO 3- λ(x= 0-1,B= Mn,Fe,Co)的三个系列的样品,并将其用作NH 3氧化的催化剂。发现即使在x= 0或x= 1时,催化剂的组成也是非化学计量的。氧的非化学计量量λ是x的函数,与晶体结构,固体缺陷,与反应性氧的反应性以及催化活性相关的氧的非化学计量量λ是x的函数。存在单相固溶体,其组成范围为x= 0至0.4。甲混溶隙出现在大约然后一个甲'乙ö 3阶段在发现。该两相区域一直延伸到立方相出现,且x = 1.0。在AB O 3的情况下掺杂低价阳离子(A ')会导致B的氧化态增加或形成氧空位。在Mn的情况下,λ和Mn 4+的浓度都与x线性相关,但在Co的情况下,由于Co 4+难以被O 2-还原,因此不可靠。,只有λ增加。Fe的情况位于以上两者之间。通过ED,EM和Mössbauer的研究,观察到铁素体系统中的空位有序。XPS,TPD,