合金中的原子排序诱导的整体变化控制着电催化剂的开/关状态
Tianyao Gong1, Guotao Qiu1, Mo-Rigen He2
1Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States.
Journal of the American Chemical Society
|December 23, 2024
概括
催化剂的设计是通过隔离几何效应来进行的. 研究人员发现,在Pd3Bi合金上的合体尺寸不同时,更大的合体在保持电子结构的同时显著提高了甲醇氧化活性.
科学领域:
- 材料科学
- 催化剂
- 表面化学
背景情况:
- 催化活性受到表面原子排列 (组合) 的影响.
- 传统材料中的组合效果和电子结构的结合阻碍了孤立分析.
- 介绍了一种新的方法来解几何和电子因素.
研究的目的:
- 开发一种方法来将几何组合效应与催化过程中的电子结构分开.
- 研究组件大小对甲醇氧化反应性的作用.
- 设计具有可调节的活点配置的催化剂.
主要方法:
- 结构不同,组成相同的Pd3Bi金属间和固体溶液合金的比较.
- 通过控制原子排序来调整组件的大小.
- 使用X射线光电子光谱 (XPS) 和X射线近边结构 (XANES) 进行电子结构的表征.
主要成果:
- 具有小组合的Pd3Bi间金属没有甲醇氧化反应.
- 较大的组件的固体溶液Pd3Bi表现出显著的甲醇氧化活性 (0.5 mA cmPd-2).
- 反应性与平均组件大小直接相关,独立于电子结构.
结论:
- 催化剂的反应性在很大程度上取决于活性位点的几何配置 (整体大小).
- 控制原子排序提供了一种调整组件大小而不会改变电子属性的途径.
- 这种方法可以通过优化特定反应的活性位点几何来实现更高效的催化剂设计.
更多相关视频
10:57Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
18.1K
10:03Characterization of Electrode Materials for Lithium Ion and Sodium Ion Batteries Using Synchrotron Radiation Techniques
Published on: November 11, 2013
25.4K
相关概念视频
Crystal Field Theory - Octahedral Complexes
26.1K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.1K
Valence Bond Theory
8.5K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.5K
Metallic Solids
18.2K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.2K
Electromotive Force
25.9K
Electricity is generated by either electrons or ions flowing through a solution or a conducting medium. This flow of electrons or specifically electrical charge is defined as an electric current. When electrons move through a wire, they generate an electric current. It can be recalled that in a redox reaction, electrons are lost and gained. In the spontaneous redox reaction of zinc with copper, when zinc is immersed in a copper ion solution, a transfer of electrons from one...
25.9K
Colors and Magnetism
11.5K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
11.5K
Trends in Lattice Energy: Ion Size and Charge
23.7K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
23.7K
