在H2O2的直接形成中通过单原子Pd@Au纳米粒子进行位置通信
Rasmus Svensson1, Henrik Grönbeck1
1Department of Physics and Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
Journal of the American Chemical Society
|May 16, 2023
概括
单原子合金催化剂,就像黄金中的一样,有效地从氧和中产生过氧化 (H2O2). 优化纳米粒子组成和条件可以提高H2O2的选择性.
科学领域:
- 催化剂
- 材料科学
- 计算化学
背景情况:
- 单原子合金 (SAA) 催化剂具有超越单金属对应物的独特特性.
- 从O2和H2中直接合成过氧化 (H2O2) 是一个关键的工业过程.
- 在黄金 (Au) 主体中嵌入的 (Pd) 是用于H2O2生产的有前途的SAA系统.
研究的目的:
- 通过基于第一原则的动力蒙特卡洛 (KMC) 方法研究嵌入在Au纳米粒子中的Pd的催化性能.
- 阐明反应机制并确定控制H2O2形成和选择性的关键因素.
- 探索SAA催化剂用于增强化反应的可能性.
主要方法:
- 基于第一原则的动力蒙特卡洛模拟方法的开发.
- 在水溶液环境中模拟Pd-Au纳米粒子.
- 反应途径的分析,包括H2分离,原子H行为和H2O2形成.
主要成果:
- 已证明有效的位点分离:Pd单体催化H2分离,而协调不足的Au位点则促进H2O2的形成.
- 确定了原子H的外热氧化还原反应,产生离子和表面负电荷.
- 显示H2O2最好通过溶解的H+与Au表面的氧物之间的反应形成.
- 证实调整纳米粒子组成和反应条件可以提高H2O2的选择性.
结论:
- 开发的KMC方法提供了对H2O2合成的SAA催化机制的见解.
- 区域隔离和Pd与Au之间的协同作用对于高效的H2O2生产至关重要.
- 该方法可用于SAA纳米粒子的其他化反应.
相关概念视频
Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
Radical Formation: Homolysis
A bond is formed between two atoms by sharing two electrons. When this bond is broken by supplying sufficient energy, either two electrons can be taken up by one atom forming ions by the cleavage called heterolysis, or the two electrons are shared by two atoms, with one each creating radicals by the cleavage called homolysis.
Heterogeneous 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...


