和氧杂质对催化乙烯化的影响
Ayesha A Alkhoori1, Andrea Ruiz-Ferrando1, Vera Giulimondi1
1Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland.
概括
单个原子保持高活性,用于与杂质的乙烯基化物单体合成. 然而,氧气通过阻断活性点显著抑制性能,强调在现实条件下需要原子分散.
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:
- 纳米结构是调整乙化单体 (VCM) 合成中的催化性能的关键.
- 现实的乙料含有氧 (O2) 和 (H2) 等杂质,这些杂质会阻碍催化剂的性能.
- 了解对单个原子 (SA) 的杂质影响对于强大的催化剂设计至关重要.
研究的目的:
- 在含有H2和O2.2的多组分料下研究单个原子 (SA) 的行为.
- 评估O2和H2杂质对VCM合成对Pt SA催化剂的影响.
- 阐明催化剂被O2抑制的机制.
主要方法:
- 使用多元组件气体 (乙,HCl,H2,O2) 的实验研究.
- 催化剂性能的表征,包括VCM产量和选择性.
- 密度功能理论 (DFT) 模拟以建模吸附和反应途径.
- 分析O2吸附过程的分析.
主要成果:
- 在存在H2的情况下,Pt SA表现出高活性和对VCM合成的选择性,没有观察到化产物.
- 同时提供氧气导致VCM产量大幅下降 (高达80%),表明严重的性能抑制.
- DFT模拟和O2脱吸数据显示,O2吸附在脱时变得更加有利,导致氧化位点阻塞.
结论:
- 保持的原子分散对于实现选择性和强大的VCM合成至关重要.
- 氧是由于氧化部位阻断,在VCM合成中Pt SA催化剂的强有力的抑制剂.
- 催化剂设计必须考虑到实际工业原料中的杂质影响.
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