从四角二形到准六角紧密包装的双金属集群的双重演变
Shisi Tang1, Endong Wang2, Yanzhen Wu3
1School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210093 China zhuyan@nju.edu.cn.
Chemical science
|June 7, 2024
概括
研究人员观察到金银集群的独特转变,从icosahedral到六角密集的结构. 这种新的转化使乙醇氧化的催化活性增加了一倍,为集群合成提供了新的见解.
科学领域:
- 纳米材料科学 科学 纳米材料科学
- 催化剂是一种催化剂.
- 集群化学 集群化学
背景情况:
- 了解双金属纳米集群的合成和特性对于开发先进的催化材料至关重要.
- 以前的研究集中在典型的生长过程上,但新的转化途径仍未得到充分探索.
研究的目的:
- 为了研究四角形和半六角形紧密包装 (hcp) 金银星团之间的二次性进化路径.
- 分析结构转换机制及其对催化性能的影响.
主要方法:
- 为了合成和转换金银集群,采用了一步减少方法.
- 最初的Au30Ag12(CCR) 24和最后的Au47Ag19(CCR) 32集群的结构特征.
- 对乙醇电催化氧化的催化反应性的评估.
主要成果:
- 确定了一种新的尺寸/结构转换机制,涉及接口缩小,核心重新排列和表面聚合.
- 四角二元体 Au30Ag12(CCR) 24 星团具有 Au18Ag8 内核,而准-hcp Au47Ag19(CCR) 32 星团具有扭曲的 Au19 内核和准-hcp 堆叠的外.
- 与icosahedral集群相比,准hcp集群的乙醇氧化催化反应性增加了两倍.
结论:
- 这项研究揭示了一个非奥斯瓦尔德生长途径用于双金属集群转换.
- 图形形状的星团表现出比hcp类星团更长的兴奋状态寿命.
- 这些发现为逆转自下而上的增长过程提供了理由,以设计具有增强催化性能的双金属集群.
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