通过在稀释合金催化剂中远程激活H-H键
Tongxin Han1, Yuanyuan Li2, Tao Wu3
1Department of Chemistry and UCR Center for Catalysis, University of California, Riverside, Riverside, California 92521, United States.
ACS catalysis
|May 9, 2024
概括
在异质催化剂的新发现中,在稀释的白金-铜 (Cu) 合金中发现白金 (Pt) 原子位于金属支接口,而不是表面. 这种独特的定位增强了特定化反应的选择性.
科学领域:
- 不同质的催化剂.
- 材料科学是一种材料科学.
- 表面化学 表面化学
背景情况:
- 在异质催化剂中,化学促进通常发生在催化剂表面.
- 假设单原子合金 (SAA) 的两个组成元素都暴露在反应物相互作用中.
- 在高度稀释的合金中,活性位点的确切位置仍然是研究领域.
研究的目的:
- 为了研究 (Pt) 原子在高度稀释的铜 (Cu) 合金催化剂中的位置.
- 了解Pt原子位置在催化性能中的作用,特别是化反应.
- 阐明这些合金系统中增强选择性背后的机制.
主要方法:
- 在现场X射线吸收光谱 (XAS) 探测当地的原子环境.
- 动力实验用于评估催化活性和选择性.
- 密度功能理论 (DFT) 计算以确定结构稳定性和反应机制.
主要成果:
- * 在Cu中高Pt稀释的Pt-Cu合金催化剂中,Pt原子位于金属纳米粒子和基体之间的内部接口.
- *与纯金属相比,这些合金催化剂对不和化不和化的选择性更高.
- * DFT计算证实了Pt在金属支接口上的稳定性,并解释了性能提升.
结论:
- * 对于合金中高度稀释的Pt,SAA中所有元素的表面暴露的常规假设并不成立.
- *金属支接口可以作为活跃催化物种的关键位置.
- 内部的 Pt 原子远程影响邻近 Cu 位点的 H2 分离的激活屏障,从而提高了催化选择性.
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