海洋铁甲皮对Ce的氧化吸收,以及使用Ce同位素对古氧估计的含义
Alain Manceau1,2, Jianlin Liao1, Yan Li1
1European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France.
概括
(Ce) 氧化和同位素分离通过维纳 (δ-MnO2) 是关键的古雷多克斯代理. 这项研究揭示了维纳石位点形成的Ce (IV) 复合体,使人们对氧化还原条件有了新的见解.
科学领域:
- 地质化学 地质化学
- 环境科学 环境科学
- 矿物学是一门学科.
背景情况:
- (Ce) 氧化和同位素分离通过维纳 (δ-MnO2) 是过去的氧化还原条件的重要代理.
- 关于Ce吸收和氧化过程的分子机制尚不清楚.
研究的目的:
- 为了阐明Ce在自然矿中的原子尺度结构.
- 调查控制Ce氧化过程的分子过程,从Ce (III) 到Ce (IV).
- 评估Ce同位素的潜力,作为一种新的古氧代谢物.
主要方法:
- 先进的高能分辨率扩展的X射线吸收细结构 (XAFS) 光谱在天然矿样本上.
- 基于密度函数理论 (DFT) 的吉布斯自由能量计算.
- 量子力学计算的同位素分离.
主要成果:
- 在维纳层边缘 (DES复合物) 和Mn{IV}空缺地点有单核Ce{IV}复合物的直接证据.
- DES复合物的水解促进了Ce (III) 到Ce (IV) 的氧化.
- 预测的136Ce/140Ce同位素分离因子在25°C时为1.2-1.3 ‰.
结论:
- 作为单核Ce (IV) 复合体,Ce被纳入维拉尼特中,以澄清清除物机制.
- 136Ce/140Ce同位素比率显示出作为一种新的,敏感的古氧代谢物具有显著的潜力.
更多相关视频
09:46Catalytic Scavenging of Plant Reactive Oxygen Species In Vivo by Anionic Cerium Oxide Nanoparticles
Published on: August 26, 2018
9.5K
04:48Setup of Capillary Electrophoresis-Inductively Coupled Plasma Mass Spectrometry CE-ICP-MS for Quantification of Iron Redox Species FeII, FeIII
Published on: May 4, 2020
8.7K
相关概念视频
Redox Equilibria: Overview
1.6K
A reduction-oxidation reaction is commonly called a redox reaction. In a redox reaction, electrons are transferred from one species to another rather than being shared between or among atoms. The reducing agent or reductant is the species that loses electrons and gets oxidized in the process. The species that gains electrons and gets reduced in the process is the oxidizing agent or oxidant. Redox reactions are represented as two separate equations called half-reactions, where one equation...
1.6K
Redox Titration: Other Oxidizing and Reducing Agents
1.5K
Besides iodine, other oxidizing or reducing agents can serve as titrants in redox titrations. Common oxidizing titrants include KMnO4, cerium(IV), and K2Cr2O7. The choice of oxidizing titrants depends on factors like stability, cost, analyte strength, and reaction rate between the analyte and titrant. KMnO4 is a strong oxidizing titrant that reduces from Mn(VII) to Mn(II) in a highly acidic solution, simultaneously oxidizing the analyte to a higher oxidation state. In this case, KMnO4 acts as a...
1.5K
Necrosis
6.8K
Necrosis is considered as an “accidental” or unexpected form of cell death that ends in cell lysis. The first noticeable mention of “necrosis” was in 1859 when Rudolf Virchow used this term to describe advanced tissue breakdown in his compilation titled “Cell Pathology”.
Morphological Manifestations of Necrosis
Necrotic cells show different types of morphological appearance depending on the type of tissue and infection. In coagulative necrosis, cells become...
Morphological Manifestations of Necrosis
Necrotic cells show different types of morphological appearance depending on the type of tissue and infection. In coagulative necrosis, cells become...
6.8K
Redox Titration: Iodimetry and Iodometry
6.2K
Iodometry and iodimetry are analytical methods used to determine the concentration of oxidizing or reducing agents using iodine. In iodometric titrations, the oxidizing analyte solution is usually acidified and treated with an excess of iodide ions, which generates an equivalent amount of iodine in equilibrium with triiodide. The released iodine is subsequently titrated directly against a standardized reducing agent. As the dilute iodine color becomes pale yellow, a few drops of freshly...
6.2K
Electron Configuration of Multielectron Atoms
65.5K
The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the 3s orbital, giving a 1s22s22p63s1 configuration. The electrons occupying the outermost shell orbital(s) (highest value of n) are called valence electrons, and those occupying the inner shell orbitals are called core electrons. Since the core electron shells correspond to noble gas electron configurations, we can abbreviate electron...
65.5K
Redox Reactions
1.2K
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
1.2K
