与CeO的相互作用
K Sohlberg1, S T Pantelides, S J Pennycook
1Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA.
Journal of the American Chemical Society
|July 6, 2001
概括
自发与低于665K的相互作用,在散装材料中形成基团. 这项研究澄清了的含量.
科学领域:
- 材料科学 材料科学 材料科学
- 表面化学 表面化学
- 计算化学计算化学
背景情况:
- 通过实验研究和之间的相互作用.
- 一个关键的争议是,原子是否会在表面化学吸收,还是会进入大批量.
研究的目的:
- 解决有关在体中的位置的争议.
- 为了确定在哪些条件下,的吸收是自发的.
主要方法:
- 使用了第一原则计算.
- 热力学论证与计算结果相结合.
主要成果:
- 的吸收是自发的,低于665K.
- 大量气形成基团,导致晶格膨胀.
- 预测的含量,OH频率和格子扩张的预测值与实验数据一致.
结论:
- 原子自发地进入了低于665K的体.
- 基组的形成和晶格扩张是大量体的关键指标.
- 这些发现使计算预测与实验观测相协调.
相关概念视频
01:29Covalent Bonds
When two atoms share electrons to complete their valence shells they create a covalent bond. An atom’s electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.A Covalent...
03:26Electron Configuration of Multielectron Atoms
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...
03:10The Equilibrium Constant
Consider the oxidation of sulfur dioxide:
03:24Common Ion Effect
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Châtelier’s principle. Consider the dissolution of silver iodide:
01:08Covalent Bonds
Overview
When two atoms share electrons to complete their valence shells, they create a covalent bond. An atom's electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.
When two atoms share electrons to complete their valence shells, they create a covalent bond. An atom's electronegativity—the force with which shared electrons are pulled towards an atom—determines how the electrons are shared. Molecules formed with covalent bonds can be either polar or nonpolar. Atoms with similar electronegativities form nonpolar covalent bonds; the electrons are shared equally. Atoms with different electronegativities share electrons unequally, creating polar bonds.
01:22Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...